P0132

Circuit Description
The PCM supplies a bias voltage of about 450 mV between the HO2S signal and low Circuit. When measured with a 10 mega ohms digital voltmeter, this may display as low as 350 mV. The oxygen sensor varies the voltage within a range of about 800 mV when the exhaust is rich, down through about 50 mV when exhaust is lean. The PCM constantly monitors the HO2S signal during closed loop operation and compensates for a rich or lean condition by decreasing or increasing injector pulse width as necessary. If the HO2S 1 voltage remains excessively high for an extended period of time, DTC P0132 will be set.

Conditions for Running the DTC
^ No active fuel trim, fuel injector circuit, Misfire, EVAP, EGR, TP, IAT, MAP, ECT, CKP, or MAF sensor DTCs present.
^ System voltage is greater than 9 volts.
^ Closed loop commanded air/fuel ratio is between 14.4 and 14.9.
^ Throttle angle is between 3% and 40%.

Conditions for Setting the DTC
HO2S 1 signal voltage remains above 975 mV during normal closed loop operation.
OR
HO2S 1 signal voltage remains above 200 mV during deceleration fuel mode operation.
Either condition for up to 50 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp on the second consecutive ignition cycle that the diagnostic runs and tails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.

Conditions for Clearing the MIL/DTC
^ The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail.
^ A last test failed (current DTC) clears when the diagnostic runs and does not fail.
^ A History DTC clears after forty consecutive warm-up cycles, if this or any Other emission related diagnostic does not report any failures.
^ Use a scan tool in order to clear the MIL/DTC.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Diagnostic Aids

Notice: Use the Connector Test Adapter kit J 35616-A for any test that requires probing the following items:
^ The PCM harness connectors
^ The electrical center fuse/relay cavities
^ The component terminals
^ The component harness connector

Using this kit will prevent damage caused by the improper probing of connector terminals. Check the following items:
^ Fuel Pressure: The system will go rich if pressure is too high. The PCM can compensate for some increase. However, if fuel pressure is too high, a DTC P0132 may be set.
Refer to Fuel System Pressure Test. Fuel System Pressure Test
^ Fuel injector(s): Refer to Fuel Inj Coil Test ECT Between 10-35 Degrees C or Fuel Inj Coil Test - ECT Outside 10-35 Degrees C. Component Tests and General Diagnostics
^ Check the EVAP Canister for fuel saturation. If the EVAP Canister is full of fuel, check the canister control and hoses.
^ Fuel Pressure Regulator: Check for a leaking fuel pressure regulator diaphragm by checking vacuum line to regulator for the presence of fuel. If a problem is found, replace the fuel pressure regulator.
^ TP Sensor: An intermittent TP sensor output will cause the system to go rich due to a false indication of the engine accelerating. Throttle Angle displayed on a scan tool should increase steadily from 0% to 100% when opening the Throttle. If not, check the TP sensor for loose mounting screws. If the TP mounting screws are OK, replace the TP sensor.
^ Shorted Heated Oxygen Sensor (HO2S): If the HO2S is internally shorted the HO2S voltage displayed on the scan tool will be over 1 volt. Disconnect the affected HO2S and jumper the HO2S low circuit to ground with the key ON, engine not running. If the displayed HO2S voltage changes from over 1000 mV to around 450 mV, replace the HO2S. Silicon contamination of the HO2S can also cause a high HO2S voltage to be indicated. This condition is indicated by a powdery white deposit on the portion of the HO2S exposed to the exhaust stream. If contamination is noticed, replace the affected HO2S.
^ Open HO2S Signal or Low Circuit or Malfunctioning HO2S: A poor connection or open in the HO2S signal or low circuit can cause the DTC to set during deceleration fuel mode. An HO2S which is malfunctioning and not allowing a full voltage swing between the rich and lean thresholds can also cause this condition. Operate the vehicle while monitoring the HO2S voltage with a scan tool. If the HO2S voltage is limited within a range between 300 mV to 600 mV, check the HO2S signal and low circuit wiring and associated terminal connections.
^ If the wiring and connections are OK, replace the affected HO2S.

The Heated Oxygen Sensors require an air reference (outside air) for proper operation. The air reference is supplied through the HO2S wiring. Inspect the HO2S wires and connections for breaks or contamination. Do not use solder to repair HO2S wiring. Solder will obstruct the air path.

Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
3. In order to determine if the engine is rich during De-acceleration Fuel Cut-Off (DFCO) operate the vehicle up to highway speed conditions and release the accelerator pedal allowing the vehicle to coast in gear. Monitor the scan tool HO2S voltage and the DFCO parameter. A rich condition will cause HO2S voltage to be above 468 mV during DFCO.
An HO2S contaminated by silicon will have a white, powdery deposit on the portion of the HO2S that is exposed to the exhaust stream. The usual cause of silica contamination is the use of un-approved silicon RTV engine gasket material, the use of silicon based sprays or fluids within the engine or coolant consumption. Phosphorus contamination also leaves a white powdery coating on the HO2S. Phosphorus contamination comes from oil consumption. If the cause of this contamination is not corrected, the replacement HO2S will also get contaminated.
6. This step checks the HO2S High signal circuit for a short to voltage.
8. An HO2S contaminated by silicon will have a white, powdery deposit on the portion of the HO2S that is exposed to the exhaust stream. The usual cause of silica contamination is the use of un-approved silicon RTV engine gasket material, the use of silicon based sprays or fluids within the engine or coolant consumption. Phosphorus contamination also leaves a white powdery coating on the HO2S. Phosphorus contamination comes from oil consumption. If the cause of this contamination is not corrected, the replacement HO2S will also get contaminated.