P0132

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The Heated Oxygen Sensor (HO2S) is a sensor used to detect oxygen-content in the exhaust. The Powertrain Control Module (PCM) supplies the sensor with a signal circuit and a ground circuit. The PCM supplies a bias voltage between the circuits. The sensor varies the voltage based on the oxygen content in the exhaust. When the exhaust stream is lean (more oxygen), the sensor produces a low voltage signal. When the exhaust stream is rich (less oxygen), the sensor produces a high voltage signal. The PCM monitors the HO2S signal during closed loop. To correct for rich or lean conditions, the PCM adjusts the injector pulse width. It HO2S bank 1 sensor 1 remains too high for a calibrated period of time, DTC P0132 will set.

CONDITIONS FOR RUNNING THE DTC
^ No MAF, TP, EVAP, IAT, MAP, ECT, AIR (if equipped), or injector DTCs set
^ EGR Flow diagnostic inactive
^ AIR diagnostic inactive
^ Catalyst diagnostic inactive
^ Closed loop fuel enabled
^ System voltage between 9-19 volts
^ Air/Fuel ratio is between 14.4-14.9
^ TP is between 3-25 percent
^ Above conditions must be met for 3 seconds.

CONDITIONS FOR SETTING THE DTC
^ HO2S bank 1 sensor 1 signal voltage remains above 900 mV (0.9 V) for approximately 50 seconds during normal closed loop fuel control.
OR
^ HO2S bank 1 sensor 1 signal voltage remains above 200 mV (0.2 V) during Deceleration Fuel Cut Off (DFCO) control.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
Check the following items:
^ Fuel pressure - Fuel pressure that is too high will cause the a rich condition. The PCM will compensate for some increase. However, if the fuel pressure is too high, DTC P0132 may set.
^ Fuel injectors - If the fuel injectors deliver improper fuel volume at the specified pressure, DTC P0132 may set. Refer to Fuel Injector Balance Test with Tech 2. Component Tests and General Diagnostics
^ EVAP canister - Check the EVAP canister and hoses for fuel saturation.
^ Silicon contamination - Silicon contamination of the HO2S sensor can also cause a high HO2S signal voltage. This condition is indicated by a powdery white deposit on the portion of the HO2S exposed to the exhaust stream.

If the condition is intermittent, refer to Intermittent Conditions Intermittent Conditions

If none of the above conditions are present, replace the HO2S sensor.

Review the front and rear long term fuel trim values on the scan tool fail records data. If both banks were rich, check for a condition that would cause a rich engine operation. If only the rear bank was rich, the rich condition is isolated to that bank (such as an intermittent open HO2S ground circuit or an intermittent short to voltage on the signal circuit).

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. Verifies whether or not the HO2S sensor voltage is switching from below 300 mV to above 600 mV, or remaining above 600 mV.
4. Verifies the bias voltage from the PCM and the condition of the circuit wiring. With the sensor disconnected, the scan tool should display a bias voltage near 450 mV.