Diagnostic Trouble Code (DTC) P2231
HO2S Signal Circuit Shorted to Heater Circuit Sensor 1
Circuit Description
The Engine control relay applies positive voltage to the heater ignition voltage circuits of the O2 sensor. The ECM applies a pulse width modulated (PWM) ground to the heater control circuit of the O2 sensor through a device within the ECM called a Driver, to control the O2 sensor rate of heating. An O2 sensor signal circuit shorted to heater control circuit DTC sets if the ECM detects the O2 sensor signal voltage is increasing or decreasing at the same rate as the O2 sensor heater control circuit.
Conditions for Running the DTC
- The O2 sensor heater control is enabled.
- The O2 sensor is at operating temperature for 10 seconds.
- The battery voltage is greater than 10.7 V.
- The calculated exhaust temperature is less than 800°C.
Conditions for Setting the DTC
- The O2 sensor voltage is 0.06 - 0.4 V.
or
- The O2 sensor voltage is 0.6 - 1.08 V.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated after 3 valid driving cycles.
- 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 P2231 - HO2S Signal Circuit Shorted to Heater Circuit Sensor 1
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | Go to |
| 2 | - Disconnect the engine oil pressure switch.
- Start the engine.
- Allow the engine to reach the normal operating temperature.
- Using the Scan Tool, select DTC display function.
Did the DTC 2231 fail this ignition? | - | Go to Step 3 | - |
| 3 | - Disconnect the appropriate O2 sensor connector.
- From the O2 sensor to the sensor wiring connector, test the following circuit for a shorted to the sensor heater control circuit fault condition:
- Reference signal circuit,
- low reference circuit,
- pump current,
- input pump current.
Did you find fault? | - | Go to Step 5 | Go to Step 4 |
| 4 | - Disconnect the ECM and the appropriate O2 sensor connector.
- From the O2 sensor wiring connector to the ECM wiring connector, test the following circuit for a shorted to the sensor heater control circuit fault condition:
- Reference signal circuit,
- low reference circuit,
- pump current,
- input pump current.
Did you find and correct the condition? | - | Go to Step 7 | Go to Step 6 |
| 5 | Replace the appropriate O2 sensor. Did you complete the replacement? | - | Go to Step 7 | - |
| 6 | Replace the ECM. Did you complete the replacement? | - | Go to Step 7 | - |
| 7 | - 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 8 |
| 8 | 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) P2232
HO2S Signal Circuit Shorted to Heater Circuit Sensor 2
Circuit Description
The Engine control relay applies positive voltage to the heater ignition voltage circuits of the O2 sensor. The ECM applies a pulse width modulated (PWM) ground to the heater control circuit of the O2 sensor through a device within the ECM called a Driver, to control the O2 sensor rate of heating. An O2 sensor signal circuit shorted to heater control circuit DTC sets if the ECM detects the O2 sensor signal voltage is increasing or decreasing at the same rate as the O2 sensor heater control circuit.
Conditions for Running the DTC
- The O2 sensor heater control is enabled.
- The O2 sensor is at operating temperature for 10 seconds.
- The battery voltage is greater than 10.7 V.
- The calculated exhaust temperature is less than 800°C.
Conditions for Setting the DTC
- The O2 sensor voltage is 0.06 - 0.4 V.
or
- The O2 sensor voltage is 0.6 - 1.08 V.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated after 3 valid driving cycles.
- 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 P2232 - HO2S Signal Circuit Shorted to Heater Circuit Sensor 2
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | Go to |
| 2 | - Disconnect the engine oil pressure switch.
- Start the engine.
- Allow the engine to reach the normal operating temperature.
- Using the Scan Tool, select DTC display function.
Did the DTC 2232 fail this ignition? | - | Go to Step 3 | - |
| 3 | - Disconnect the appropriate O2 sensor connector.
- From the O2 sensor to the sensor wiring connector, test the following circuit for a shorted to the sensor heater control circuit fault condition:
- Reference signal circuit,
- low reference circuit,
- pump current,
- input pump current.
Did you find fault? | - | Go to Step 5 | Go to Step 4 |
| 4 | - Disconnect the ECM and the appropriate O2 sensor connector.
- From the O2 sensor wiring connector to the ECM wiring connector, test the following circuit for a shorted to the sensor heater control circuit fault condition:
- Reference signal circuit,
- low reference circuit,
- pump current,
- input pump current.
Did you find and correct the condition? | - | Go to Step 7 | Go to Step 6 |
| 5 | Replace the appropriate O2 sensor. Did you complete the replacement? | - | Go to Step 7 | - |
| 6 | Replace the ECM. Did you complete the replacement? | - | Go to Step 7 | - |
| 7 | - 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 8 |
| 8 | 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) P2270
HO2S Signal Stuck Lean Sensor 2
Circuit Description
The Engine control relay applies positive voltage to the heater ignition voltage circuits of the O2 sensor. The ECM applies a pulse width modulated (PWM) ground to the heater control circuit of the O2 sensor through a device within the ECM called a Driver, to control the O2 sensor rate of heating. The ECM applies a voltage of approximately 450 mV between the reference signal circuit and low reference circuit of the O2 sensor while the sensor temperature is less than the operating range. Once the O2 sensor reaches operating temperature, the sensor varies this reference signal voltage, which constantly fluctuates between the high voltage output and the low voltage output. The ECM monitors, stores and evaluates the O2 sensor voltage fluctuation information to determine the level of oxygen concentration in the exhaust.
Conditions for Running the DTC
- The O2 sensor lambda control is enabled.
- Air mass flow is greater than 40 kg/h.
- Active oscillation check finished.
Conditions for Setting the DTC
- The O2 sensor signal voltage is greater than target voltage.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated after 3 valid driving cycles.
- 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 P2270 - HO2S Signal Stuck Lean Sensor 2
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | Go to |
| 2 | - Disconnect the engine oil pressure switch.
- Start the engine.
- Allow the engine to reach the normal operating temperature.
- Using the Scan Tool, select DTC display function.
Did the DTC 2270 fail this ignition? | - | Go to Step 3 | - |
| 3 | Are DTCs relating to the heater circuit of the O2 sensor also set? | - | - | Go to Step 4 |
| 4 | - Disconnect the appropriate O2 sensor wiring connector.
- Switch on the ignition with the engine not running.
- Using a digital multimeter, measure the voltage between the O2 sensor reference signal circuit and low reference circuit.
Does the multimeter display specified value? | - | Go to Step 7 | Go to Step 5 |
| 5 | Test the reference signal circuit of the O2 sensor 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 10 | Go to Step 6 |
| 6 | Test the low reference circuit of the O2 sensor 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 10 | Go to Step 9 |
| 7 | Test or inspect for the following conditions that may cause the O2 sensor to detect an incorrect air/fuel mixture: - lean or rich fuel injector fuel delivery,
- restricted air intake system,
- contaminated fuel,
- low fuel line pressure,
- exhaust leak near the O2 sensor, and
- leak in the crankcase or vacuum line.
Did you find and correct the condition? | - | Go to Step 10 | Go to Step 8 |
| 8 | Replace the appropriate O2 sensor. Did you complete the replacement? | - | Go to Step 10 | - |
| 9 | Replace the ECM. Did you complete the replacement? | - | Go to Step 10 | - |
| 10 | - 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 2 |
| 11 | 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) P2271
HO2S Signal Stuck Rich Sensor 2
Circuit Description
The Engine control relay applies positive voltage to the heater ignition voltage circuits of the O2 sensor. The ECM applies a pulse width modulated (PWM) ground to the heater control circuit of the O2 sensor through a device within the ECM called a Driver, to control the O2 sensor rate of heating. The ECM applies a voltage of approximately 450 mV between the reference signal circuit and low reference circuit of the O2 sensor while the sensor temperature is less than the operating range. Once the O2 sensor reaches operating temperature, the sensor varies this reference signal voltage, which constantly fluctuates between the high voltage output and the low voltage output. The ECM monitors, stores and evaluates the O2 sensor voltage fluctuation information to determine the level of oxygen concentration in the exhaust.
Conditions for Running the DTC
- The O2 sensor lambda control is enabled.
- Air mass flow is greater than 40 kg/h.
- Active oscillation check finished.
Conditions for Setting the DTC
- The O2 sensor signal voltage is less than target voltage.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will be illuminated after 3 valid driving cycles.
- 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 P2271 - HO2S Signal Stuck Rich Sensor 2
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | Go to |
| 2 | - Disconnect the engine oil pressure switch.
- Start the engine.
- Allow the engine to reach the normal operating temperature.
- Using the Scan Tool, select DTC display function.
Did the DTC 2271 fail this ignition? | - | Go to Step 3 | - |
| 3 | Are DTCs relating to the heater circuit of the O2 sensor also set? | - | - | Go to Step 4 |
| 4 | - Disconnect the appropriate O2 sensor wiring connector.
- Switch on the ignition with the engine not running.
- Using a digital multimeter, measure the voltage between the O2 sensor reference signal circuit and low reference circuit.
Does the multimeter display specified value? | - | Go to Step 7 | Go to Step 5 |
| 5 | Test the reference signal circuit of the O2 sensor 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 10 | Go to Step 6 |
| 6 | Test the low reference circuit of the O2 sensor 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 10 | Go to Step 9 |
| 7 | Test or inspect for the following conditions that may cause the O2 sensor to detect an incorrect air/fuel mixture: - lean or rich fuel injector fuel delivery,
- restricted air intake system,
- contaminated fuel,
- low fuel line pressure,
- exhaust leak near the O2 sensor, and
- leak in the crankcase or vacuum line.
Did you find and correct the condition? | - | Go to Step 10 | Go to Step 8 |
| 8 | Replace the appropriate O2 sensor. Did you complete the replacement? | - | Go to Step 10 | - |
| 9 | Replace the ECM. Did you complete the replacement? | - | Go to Step 10 | - |
| 10 | - 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 2 |
| 11 | 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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