P0132

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) supplies a bias voltage of about 450 mV between the heated oxygen sensor high signal circuit and the (HO2S) low reference circuits. When measured with a 10 megohm digital multimeter, the voltage may read as low as 350 mV. The oxygen sensor signal varies from about 800 mV when the exhaust is rich, to about 50 mV when the exhaust is lean. The PCM constantly monitors the HO2S signal during closed loop operation and compensates for a rich or a lean condition by decreasing or increasing the injector pulse width as necessary. If the HO2S 1 voltage remains excessively high for an extended time, DTC P0132 will set.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0201, P0202- P0206, P0410, P0440, P0442, P0443, P0446, P0449, or P1441 are not set.
^ The system voltage is more than 9 volts.
^ The Closed Loop commanded air/fuel ratio is between 12-16.5.
^ The throttle angle is between 3-35 percent.

CONDITIONS FOR SETTING THE DTC
^ The HO2S 1 signal voltage remains above 975 mV during normal closed loop operation.

OR

^ The HO2S 1 signal voltage remains above 200 mV during deceleration fuel mode operation.

Either of the above conditions is present for up to 50 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions.

Check the following items:
^ The fuel pressure-The system will go rich if pressure is too high. The PCM can compensate for some increase. However, if the fuel pressure is too high, DTC P0132 may be set. Refer to DTC P0132.
^ The fuel injectors-Refer to Fuel Injector Balance Test with Special Tool. Component Tests and General Diagnostics
^ Inspect the (EVAP) canister for fuel saturation. If the canister is full of fuel, inspect the canister and hoses.
^ Disconnect the (MAF) sensor and see if rich condition is corrected. If so, replace the MAF sensor. Refer to Mass Air Flow (MAF) Sensor Replacement.
^ Test for a leaking fuel pressure regulator diaphragm by checking the vacuum line to the regulator for the presence of fuel.
^ An intermittent (TP) sensor output will cause the system to go rich due to a false indication of the engine accelerating.
^ A shorted Heated Oxygen Sensor (HO2S)- If the HO2S is internally shorted, the HO2S voltage displayed on the scan tool will be more than 1.0 volt. Disconnect the affected HO2S and jumper the HO2S low reference circuit to ground with the key ON, and the engine OFF. If the displayed HO2S voltage changes from more than 1000 mV to approximately 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 that is exposed to the exhaust stream. If you notice contamination, replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) 1 Replacement or Heated Oxygen Sensor (HO2S) 2 Replacement.
^ An open HO2S high signal or low reference circuit or inoperative HO2S-A poor connection or an open in the HO2S high signal or low reference circuit can cause the DTC to set during deceleration fuel mode. An HO2S which is inoperative 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 of 300 mV- 600 mV, check the HO2S high signal and low reference circuit wiring and the associated terminal connections. If the wiring and connections are OK, replace the HO2S. Refer to Heated Oxygen Sensor (HO2S) 1 Replacement or Heated Oxygen Sensor (HO2S) 2 Replacement.

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

Check for the following conditions:
^ Poor terminal connection-Inspect the harness connectors for the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal to wire connections- Use a corresponding mating terminal to test for proper tension.
^ Damaged harness-Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault.
^ PCM and engine grounds for clean and secure connections-If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION

Steps 1-3:

Steps 4-11:

The number below refer to step number on the diagnostic table.
3. This DTC failing during deceleration fuel mode operation, when the vehicle speed is more than 40 km/h (25 mph) and the TP angle is less than 3 percent, may indicate a condition described in Diagnostic Aids. If this DTC test passes while the Failure Records conditions are being duplicated, an intermittent condition is indicated. Review the Failure Records vehicle mileage since the diagnostic test last failed. This may help to determine how often the condition that caused the DTC to be set occurs.