Diagnostic Trouble Code (DTC) P2121
Accelerator Pedal Position (APP) Sensor 1 Performance
Circuit Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 volt at rest to above 4 volts when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volts at rest to more than 2 volts with the accelerator pedal fully depressed.
Conditions for Running the DTC
- Battery voltage is greater than 8 V.
Conditions for Setting the DTC
Difference between APP Sensor 1 voltage and APP sensor 2 voltage is greater than expected.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
- Inspect the ECM connectors for signs for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circit or momponent conditions found during diagnostic testing.
- When the ECM detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual conditio may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
- For an intermittent condition, refer to "Intermittents".
DTC P2121 - Accelerator Pedal Position (APP) Sensor 1 Performance
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | Important : Do NOT depress the accelerator pedal. - Start the engine.
- Observe the DTC information with a scan tool.
Did any other throttle actuator control (TAC) module or accelerator pedal position (APP) sensor DTC set except P1125? | - | Go to applicable DTC table | Go to Step 3 |
| 3 | Observe the APP sensor Agree/Disagree parameters with a scan tool. Does the scan tool indicate Disagree for any of the APP Agree/Disagree parameters? | - | Go to Step 5 | Go to Step 4 |
| 4 | - Turn ON the ignition, with the engine OFF.
- Observe the APP sensor angles for both APP sensors with a scan tool.
- Slowly depress the accelerator pedal, stopping at 25, 50, 75, and 100 percent.
- Slowly release the accelerator pedal, stopping at 75, 50, 25, and 0 percent.
Does the scan tool indicate the difference between APP sensor 1 voltage and the APP sensor 2 voltage is greater than the value specified during the above test? | 0.716 V, 0.273 V when both APP 1.2 are greater than 1.25 V, 1.074 V when both APP 1.2 are greater than 3.35 V. | | Go to Step 5 |
| 5 | - Turn OFF the ignition.
- Disconnect the APP sensor harness connector.
- Connect a fused jumper between the APP sensor 1 5-volt reference circuit and ground.
- Turn ON the ignition, with the engine OFF.
- Observe the APP sensor 1 voltage parameter with a scan tool.
Does the scan tool indicate APP sensor 1 voltage is at the specified value? | 0.0 V | Go to Step 6 | Go to Step 10 |
| 6 | - Connect a fused jumper between the APP sensor 1 5-volt reference circuit and the APP sensor 1 low reference circuit.
- Observe the APP sensor 1 voltage parameter with a scan tool.
Does the scan tool indicate APP sensor 1 voltage is at specified value? | 0.0 V | Go to Step 7 | Go to Step 11 |
| 7 | - Connect a fused jumper between the APP sensor 1 signal circuit and the APP sensor 1 5-volt reference circuit.
- Observe the APP sensor 1 voltage parameter with a scan tool.
Does the scan tool indicate APP sensor 1 voltage is near the specified value? | 5 V | Go to Step 13 | Go to Step 8 |
| 8 | Test for a short between the APP sensor 1 signal circuit and all other APP circuits at the APP sensor harness connector with a digital multimeter (DMM). Does the DMM indicate a short to another circuit? | - | Go to Step 9 | Go to Step 12 |
| 9 | - Turn OFF the ignition.
- Disconnect both of the ECM harness connectors.
- Test for a short between the APP sensor 1 signal circuit and all other APP circuits at the APP sensor harness connector with a DMM.
Did you find and correct the condition? | - | Go to Step 17 | Go to Step 14 |
| 10 | - Turn OFF the ignition.
- Disconnect the ECM harness connector containing the APP circuits.
- Test the APP sensor 1 5-volt reference circuit for an open or high resistance with a DMM.
Did you find and correct the condition? | - | Go to Step 17 | Go to Step 14 |
| 11 | - Turn OFF the ignition.
- Disconnect the ECM harness connector containing the APP circuits.
- Test the APP sensor 1 low-reference circuit for an open or high resistance with a DMM.
Did you find and correct the condition? | - | Go to Step 17 | Go to Step 14 |
| 12 | - Turn OFF the ignition.
- Disconnect the ECM harness connector containing the APP circuits.
- Test the APP sensor 1 signal circuit for an open or high resistance with a DMM.
Did you find an open or high resistance? | - | Go to Step 17 | Go to Step 14 |
| 13 | Inspect for poor connections at the harness connector of the APP sensor. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 15 |
| 14 | Inspect for poor connections at the harness connectors of the ECM. Did you find and correct the condition? | - | Go to Step 17 | Go to Step 16 |
| 15 | Replace the APP sensor assembly. Did you complete the replacement? | - | Go to Step 17 | - |
| 16 | Replace the ECM. Did you complete the replacement? | - | Go to Step 17 | - |
| 17 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds. Start the engine.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 18 |
| 18 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | - | | System OK |
Diagnostic Trouble Code (DTC) P2122
Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage
Circuit Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 volt at rest to above 4 volts when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volts at rest to more than 2 volts with the accelerator pedal fully depressed.
Conditions for Running the DTC
- Battery voltage is greater than 8 V.
Conditions for Setting the DTC
APP sensor voltage is less than 0.898 V.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
DTC P2122 - Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Turn ON the ignition, with the engine OFF.
- Observe the accelerator pedal position (APP) Sensor 1 voltage parameter with a scan tool.
Is the voltage less than the specified value? | 0.49 V | Go to Step 5 | Go to Step 3 |
| 3 | - Observe the DTC information with a scan tool.
- Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position.
- Repeat this action several times.
Did the DTC fail this ignition? | - | Go to Step 13 | Go to Step 4 |
| 4 | - Observe the Freeze Frame/Failure Records for this DTC.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 5 | |
| 5 | - Turn OFF the ignition.
- Disconnect the APP sensor harness connector.
- Turn ON the ignition, with the engine OFF.
- Set-up a DMM to test amperage on the 400 mA scale.
- Measure the amperage from the 5-volt reference circuit of APP sensor 1 to the low reference circuit of APP sensor 1, with a DMM.
Is the amperage more than the specified value? | 80 mV | Go to Step 6 | Go to Step 9 |
| 6 | - Turn OFF the ignition.
- Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the APP sensor 1 and the signal circuit of the APP sensor 1.
- Turn ON the ignition, with the engine OFF.
- Observe the APP sensor 1 voltage parameter with a scan tool.
Is the voltage within the specified range? | 4.8-5.2 V | Go to Step 7 | Go to Step 10 |
| 7 | - Turn OFF the ignition.
- Remove the engine control module ECM/TCM fuse from the engine fuse block.
- Measure the resistance from the low reference circuit of the APP sensor 1 to a good ground, with a DMM.
Is the resistance less than the specified value? | 10 ohms | Go to Step 11 | Go to Step 8 |
| 8 | - Disconnect the ECM.
- Test the low reference circuit of the APP sensor 1 for an open or high resistance.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 9 | - Test the 5-volt reference circuit of the APP sensor 1 for the following conditions:
- A short to ground
- High resistance
- An open circuit
- Repair as necessary.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 10 | - Test the signal circuit of the APP sensor 1 for the following conditions:
- A short to ground
- High resistance
- An open circuit
- Repair as necessary.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 11 | Test for an intermittent and for a poor connection at the APP assembly. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 13 |
| 12 | Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 14 |
| 13 | Replace the APP assembly. Did you complete the replacement? | - | Go to Step 15 | - |
| 14 | Replace the ECM. Did you complete the replacement? | - | Go to Step 15 | - |
| 15 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 16 |
| 16 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
Diagnostic Trouble Code (DTC) P2123
Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage
Circuit Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 volt at rest to above 4 volts when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volts at rest to more than 2 volts with the accelerator pedal fully depressed.
Conditions for Running the DTC
Conditions for Setting the DTC
APP sensor voltage is greater than 4.824 V .
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
DTC P2123 - Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Turn ON the ignition, with the engine OFF.
- Observe the accelerator pedal position (APP) sensor 1 voltage parameter, with a scan tool.
Is the voltage less than the specified value? | 4.0 V | Go to Step 5 | Go to Step 3 |
| 3 | - Observe the DTC information with a scan tool.
- Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position.
- Repeat this action several times.
Did the DTC fail this ignition? | - | Go to Step 13 | Go to Step 4 |
| 4 | - Observe the Freeze Frame/Failure Records for this DTC.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 5 | |
| 5 | - Turn OFF the ignition.
- Disconnect the APP sensor harness connector.
- Turn ON the ignition, with the engine OFF.
- Observe the APP sensor 1 voltage with the scan tool.
Is the voltage less than the specified value? | 0.1 V | Go to Step 6 | Go to Step 10 |
| 6 | Measure the voltage from the 5-volt reference circuit of the APP sensor 1 to a good ground, with a DMM. Is the voltage more than the specified value? | 6 V | Go to Step 9 | Go to Step 7 |
| 7 | - Turn OFF the ignition.
- Remove the engine control module ECM/TCM fuse from the engine fuse block.
- Measure the resistance from the low reference circuit of APP sensor 1 to a good ground, with a DMM.
Is the resistance less than the specified value? | 10 ohms | Go to Step 11 | Go to Step 8 |
| 8 | - Turn OFF the ignition.
- Disconnect the ECM.
- Test the low reference circuit of the APP sensor 1 for an open, for a short to voltage, or for a high resistance.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 9 | Test the 5-volt reference circuit of the APP sensor 1 for a short to voltage. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 10 | Test the signal circuit of the APP sensor 1 for a short to voltage. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 11 | Test for shorted terminals and poor connections at the APP sensor. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 13 |
| 12 | Test for shorted terminals and poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 14 |
| 13 | Replace the accelerator pedal assembly. Did you complete the replacement? | - | Go to Step 15 | - |
| 14 | Replace the ECM. Did you complete the replacement? | - | Go to Step 15 | - |
| 15 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 16 |
| 16 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
Diagnostic Trouble Code (DTC) P2127
Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage
Circuit Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 volt at rest to above 4 volts when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volts at rest to more than 2 volts with the accelerator pedal fully depressed.
Conditions for Running the DTC
Conditions for Setting the DTC
APP sensor voltage is less than 0.820 V.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
DTC P2127 - Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Turn ON the ignition, with the engine OFF.
- Observe the accelerator pedal position (APP) Sensor 2 voltage parameter with a scan tool.
Is the voltage less than the specified value? | 0.49 V | Go to Step 5 | Go to Step 3 |
| 3 | - Observe the DTC information with a scan tool.
- Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position.
- Repeat this action several times.
Did the DTC fail this ignition? | - | Go to Step 13 | Go to Step 4 |
| 4 | - Observe the Freeze Frame/Failure Records for this DTC.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 5 | |
| 5 | - Turn OFF the ignition.
- Disconnect the APP sensor harness connector.
- Turn ON the ignition, with the engine OFF.
- Set-up a DMM to test amperage on the 400 mA scale.
- Measure the amperage from the 5-volt reference circuit of APP sensor 2 to the low reference circuit of APP sensor 2, with a DMM.
Is the amperage more than the specified value? | 80 mV | Go to Step 6 | Go to Step 9 |
| 6 | - Turn OFF the ignition.
- Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the APP sensor 2 and the signal circuit of the APP sensor 2.
- Turn ON the ignition, with the engine OFF.
- Observe the APP sensor 2 voltage parameter with a scan tool.
Is the voltage within the specified range? | 4.8-5.2 V | Go to Step 7 | Go to Step 10 |
| 7 | - Turn OFF the ignition.
- Remove the engine control module ECM/TCM fuse from the engine fuse block.
- Measure the resistance from the low reference circuit of the APP sensor 2 to a good ground, with a DMM.
Is the resistance less than the specified value? | 10 ohms | Go to Step 11 | Go to Step 8 |
| 8 | - Disconnect the ECM.
- Test the low reference circuit of the APP sensor 2 for an open or high resistance.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 9 | - Test the 5-volt reference circuit of the APP sensor 2 for the following conditions:
- A short to ground
- High resistance
- An open circuit
- Repair as necessary.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 10 | - Test the signal circuit of the APP sensor 2 for the following conditions:
- A short to ground
- High resistance
- An open circuit
- Repair as necessary.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 11 | Test for an intermittent and for a poor connection at the APP assembly. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 13 |
| 12 | Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 14 |
| 13 | Replace the APP assembly. Did you complete the replacement? | - | Go to Step 15 | - |
| 14 | Replace the ECM. Did you complete the replacement? | - | Go to Step 15 | - |
| 15 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 16 |
| 16 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
Diagnostic Trouble Code (DTC) P2128
Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage
Circuit Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 volt at rest to above 4 volts when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volts at rest to more than 2 volts with the accelerator pedal fully depressed.
Conditions for Running the DTC
- Battery voltage is greater than 8 V.
Conditions for Setting the DTC
- APP sensor voltage is greater than 4.824 V.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
DTC P2128 - Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Turn ON the ignition, with the engine OFF.
- Observe the accelerator pedal position (APP) sensor 2 voltage parameter, with a scan tool.
Is the voltage less than the specified value? | 4.0 V | Go to Step 5 | Go to Step 3 |
| 3 | - Observe the DTC information with a scan tool.
- Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position.
- Repeat this action several times.
Did the DTC fail this ignition? | - | Go to Step 13 | Go to Step 4 |
| 4 | - Observe the Freeze Frame/Failure Records for this DTC.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 5 | |
| 5 | - Turn OFF the ignition.
- Disconnect the APP sensor harness connector.
- Turn ON the ignition, with the engine OFF.
- Observe the APP sensor 2 voltage with the scan tool.
Is the voltage less than the specified value? | 0.1 V | Go to Step 6 | Go to Step 10 |
| 6 | Measure the voltage from the 5-volt reference circuit of the APP sensor 2 to a good ground, with a DMM. Is the voltage more than the specified value? | 6 V | Go to Step 9 | Go to Step 7 |
| 7 | - Turn OFF the ignition.
- Remove the engine control module ECM/TCM fuse from the engine fuse block.
- Measure the resistance from the low reference circuit of APP sensor 2 to a good ground, with a DMM.
Is the resistance less than the specified value? | 10 ohms | Go to Step 11 | Go to Step 8 |
| 8 | - Turn OFF the ignition.
- Disconnect the ECM.
- Test the low reference circuit of the APP sensor 2 for an open, for a short to voltage, or for a high resistance.
Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 9 | Test the 5-volt reference circuit of the APP sensor 2 for a short to voltage. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 10 | Test the signal circuit of the APP sensor 2 for a short to voltage. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 12 |
| 11 | Test for shorted terminals and poor connections at the APP sensor. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 13 |
| 12 | Test for shorted terminals and poor connections at the ECM. Did you find and correct the condition? | - | Go to Step 15 | Go to Step 14 |
| 13 | Replace the accelerator pedal assembly. Did you complete the replacement? | - | Go to Step 15 | - |
| 14 | Replace the ECM. Did you complete the replacement? | - | Go to Step 15 | - |
| 15 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 16 |
| 16 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
Diagnostic Trouble Code (DTC) P2135
Throttle Position (TP) Sensor 1-2 Correlation
Circuit Description
The throttle position (TP) sensor incorporates 2 TP sensors into one housing. TP sensor 1 and TP sensor 2 each have a 5-volt reference circuit supplied by the ECM. The ECM supplies each TP sensor with a low reference circuit. Each TP sensor supplies the ECM with a signal voltage that is proportional to the throttle plate position. The TP signal voltages are opposite from one another. TP sensor 1 is pulled up to reference voltage as the throttle plate is opened. The TP sensor 2 is pulled down to low reference as the throttle plate is opened.
Conditions for Running the DTC
Conditions for Setting the DTC
- Difference between normalized values of TPS1 and TPS2 is greater than expected for a certain period of time.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
- Inspect the ECM connectors for signs of water intrusion. When water intrusion occurs, multiple DTCs could be set with no DTC circuit or component conditions found during diagnostic testing.
- When the ECM detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests that run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the Capture Info.
- If this DTC is determined to be intermittent, refer to "Intermittents".
DTC P2135 - Throttle Position (TP) Sensor 1-2 Correlation
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Turn ON the ignition, with the engine OFF.
- Observe the throttle position (TP) sensor 1 and sensor 2 with a scan tool.
Does the scan tool TP sensor 1 and sensor 2 parameter indicate Disagree? | - | Go to Step 4 | Go to Step 3 |
| 3 | - Remove the air inlet duct from the throttle body.
- Disconnect the throttle actuator motor harness connector.
- Slowly, manually open the throttle plate to wide open throttle (WOT) and back to the closed throttle position several times while observing the scan tool TP sensor parameter.
Does the TP sensor parameter change from Agree to Disagree during the above test? | - | Go to Step 17 | Go to Step 4 |
| 4 | - Disconnect the throttle position (TP) sensor harness connector.
- Disconnect the throttle actuator control (TAC) module harness connectors.
- Test the TP sensor 1 5-volt reference circuit for resistance.
Did the DTC fail this ignition? | - | Go to Step 19 | Go to Step 5 |
| 5 | Test for a short between the TP sensor 1 5-volt reference circuit and all other ECM circuits. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 6 |
| 6 | Test the TP sensor 1 signal circuit for resistance. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 7 |
| 7 | Test for a short between the TP sensor 1 signal circuit and all other ECM circuits Did you find and correct the condition? | 10 ohms | Go to Step 19 | Go to Step 8 |
| 8 | Test the TP sensor 1 low reference circuit for resistance. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 9 |
| 9 | Test for a short between the TP sensor 1 low reference circuit and all other ECM circuits. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 10 |
| 10 | Test the TP sensor 2 5-volt reference circuit for resistance. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 11 |
| 11 | Test for a short between the TP sensor 2 5-volt reference circuit and all other ECM circuits. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 12 |
| 12 | Test the TP sensor 2 signal circuit for resistance. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 13 |
| 13 | Test for a short between the TP sensor 2 signal circuit and all other ECM circuits Did you find and correct the condition? | - | Go to Step 19 | Go to Step 14 |
| 14 | Test the TP sensor 2 low reference circuit for resistance. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 15 |
| 15 | Test for a short between the TP sensor 2 low reference circuit and all other ECM circuits. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 16 | Inspect for poor connections at the harness connector of the ECM. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 17 |
| 17 | Inspect for poor connections at the harness connector of the TP sensor. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 18 |
| 18 | Replace the throttle body assembly. Did you complete the replacement? | - | Go to Step 19 | - |
| 19 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records.
Does the DTC run and pass? | - | Go to Step 20 | Go to Step 2 |
| 20 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
Diagnostic Trouble Code (DTC) P2138
Accelerator Pedal Position (APP) Sensor 1 – 2 Correlation
Circuit Description
The accelerator pedal assembly contains two accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1.0 volt at rest to above 4 volts when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 volts at rest to more than 2 volts with the accelerator pedal fully depressed.
Conditions for Running the DTC
- Battery voltage is greater than 8 V.
- APP sensor voltage is greater than 1.23 V.
Conditions for Setting the DTC
- If the ECM detects that the difference between APP sensor 1 and 2 signal voltage is more than a predetermined value, this DTC sets.
- APP sensor 1 voltage is greater than 1.5 V.
- Any sensor error from APP sensor 1 & 2.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
DTC P2138 - Accelerator Pedal Position (APP) Sensor 1 – 2 Correlation
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Turn ON the ignition, with the engine OFF.
- Perform the following tests:
- Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times.
- Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times.
- Observe the accelerator pedal position (APP) sensors 1 and 2 parameter with a scan tool.
Does the scan tool display Agree? | 4.0 V | Go to Step 4 | Go to Step 3 |
| 3 | Observe the DTC information with a scan tool. Is DTC P0122, P0123, P0222, P0223, P2122, P2123, P2127, P2128 also set? | - | Go to applicable DTC table | Go to Step 5 |
| 4 | - Observe the Freeze Frame/Failure Records for this DTC.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 5 | |
| 5 | - Turn OFF the ignition.
- Disconnect the APP sensor harness connector.
- Turn ON the ignition, with the engine OFF.
- Connect a test lamp between the 5-volt reference circuit of the APP sensor 1 and a good ground. 5.Connect a DMM to the probe of the test lamp and a good ground.
Is the voltage within the specified range? | 4.8-5.1 V | Go to Step 6 | Go to Step 11 |
| 6 | - Connect a test lamp between the 5-volt reference circuit of the APP sensor 2 and a good ground.
- Connect a DMM to the probe of the test lamp and a good ground.
Is the voltage within the specified range? | 4.8-5.1 V | Go to Step 7 | Go to Step 11 |
| 7 | - Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the signal circuit of the APP sensor 1.
- Observe the APP sensor 1 voltage parameter with a scan tool.
Is the voltage more than the specified value? | 4.8 V | Go to Step 8 | Go to Step 12 |
| 8 | - Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the signal circuit of the APP sensor 2.
- Observe the APP sensor 2 voltage parameter with a scan tool.
Is the voltage more than the specified value? | 4.8 V | Go to Step 9 | Go to Step 12 |
| 9 | - Turn OFF the ignition.
- Remove the engine control module ECM/TCM fuse from the engine fuse block.
- Measure the resistance from the low reference circuit of the APP sensor 1 to a good ground with a DMM.
Is the resistance less than the specified value? | 10 ohms | Go to Step 10 | Go to Step 13 |
| 10 | Measure the resistance from the low reference circuit of the APP sensor 2 to a good ground with a DMM. Is the resistance less than the specified value? | 10 ohms | Go to Step 14 | Go to Step 13 |
| 11 | Test the 5-volt reference circuit of the APP sensor 1 or 2 for a high resistance, a short to ground, a short to voltage, or for an open. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 12 | Test the signal circuit of the APP sensor 1 or 2 for a high resistance, a short to ground, or for an open. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 13 | Test the low reference circuit of the APP sensor 1 or 2 for a high resistance, or for an open. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 14 | Test the signal circuit of APP sensor 1 for a short to the signal circuit of APP sensor 2. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 15 | Test for an intermittent and for a poor connection at the APP sensor. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 17 |
| 16 | Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 18 |
| 17 | Replace the APP sensor. Did you complete the replacement? | - | Go to Step 19 | - |
| 18 | Replace the ECM. Did you complete the replacement? | - | Go to Step 19 | - |
| 19 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 20 |
| 20 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
Diagnostic Trouble Code (DTC) P2176
Throttle Control Lower Position not Learned
Circuit Description
The ECM monitors and evaluates the accelerator pedal position (APP) sensors signal voltage along with other sensor inputs to determine the desired throttle opening. To control the throttle plate movement, the ECM applies a pulse width modulated (PWM) signal voltage to the throttle actuator motor through the throttle actuator motor control circuits. In addition, the ECM monitors the signal voltage applied to the throttle actuator motor control circuit. A TAC motor control circuit DTC sets if the ECM detects a fault condition in the TAC circuits or motor performance.
Conditions for Running the DTC
- Engine is new.
- Electronic throttle controller is new.
- Under throttle control actuator initialization.
Conditions for Setting the DTC
- Engine speed is greater than 250 rpm.
- Vehicle speed is greater than 0 km/h.
- Acceleration pedal position is greater than or equal to 14.902 %.
- Engine coolant temperature is less than 5.3 °C or greater than 100.5 °C.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three or four consecutive driving cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
- Disconnecting the ECM battery feed for 10 seconds.
DTC P2176 - Throttle Control Lower Position not Learned
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | |
| 2 | - Switch off the ignition for 30 seconds.
- Operate the vehicle within the conditions for running the DTC.
- Start the engine.
- Quickly depress the accelerator pedal to wide-open throttle then release pedal. Repeat this procedure several times.
- Using the Scan Tool, select the DTC display function.
Did the DTC P2176 fail this ignition? | - | Go to Step 3 | - |
| 3 | Is DTC P0121, P0122, P0123, P0221, P0222 or P0223 also set? | - | Go to applicable DTC table | - |
| 4 | - Disconnect the throttle actuator wiring connector.
- Inspect the throttle plate for the following:
- excessive dirt build-up in the throttle body,
- not in rest position,
- binding open or binding close,
- binding when moving from open to close or close to open position, and
- free to move open or close without spring pressure.
Did you find and correct the condition? | - | Go to Step 13 | Go to Step 5 |
| 5 | Inspect the engine for fault conditions that causes incorrect idle speed. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 6 |
| 6 | - Switch on the ignition with the engine not running.
- Using a digital multimeter, measure the voltage between the TAC positive circuit and the ECM housing.
Is the voltage within the specified range? | 2 - 4 V | Go to Step 7 | Go to Step 9 |
| 7 | - Switch on the ignition with the engine not running.
- Using a digital multimeter, measure the voltage between the TAC positive control circuit and the ECM housing.
Is the voltage within the specified range? | 2 - 4 V | Go to Step 8 | Go to Step 9 |
| 8 | - Switch off the ignition.
- Connect a test lamp between the positive and negative control circuit of the TAC.
- Switch on the ignition for about 5 seconds then switch off while observing the test lamp.
Does the test lamp illuminate briefly each time the ignition cycles? | - | Go to Step 11 | Go to Step 10 |
| 9 | Test the TAC control circuit that measured outside the specified value for a high resistance, open circuit, short to ground or short to voltage fault condition. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 12 |
| 10 | Test the positive and negative control circuits of the TAC for a shorted together fault condition. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 12 |
| 11 | Replace the throttle body assembly. Did you complete the replacement? | - | Go to Step 13 | - |
| 12 | Replace the ECM. Did you complete the replacement? | - | Go to Step 13 | - |
| 13 | - Clear the DTCs with a scan tool.
- Turn OFF the ignition for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? | - | Go to Step 2 | Go to Step 14 |
| 14 | Check if any additional DTCs are set. Are there any DTCs that have not been diagnosed? | - | Go to applicable DTC table | System OK |
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