DTC P0132 or P0152

Circuit Description

The powertrain control module (PCM) supplies a voltage of approximately 450 mV between the HO2S high and low signal circuits. The heated oxygen sensor varies the voltage from approximately 1,000 mV when the exhaust is rich, to approximately 10 mV when the exhaust is lean.

The PCM monitors and stores the heated oxygen sensor (HO2S) voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period, and determines if the majority of the samples are out of the operating range.

The PCM monitors the HO2S voltage for being fixed above a predetermined voltage. If the PCM detects the voltage is above a predetermined voltage, a DTC sets.

Conditions for Running the DTC

• DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1415, P1416, P1441, P1514, P1515, P1516, P1517, or P1518 are not set.
• The ignition 1 signal is between 9-18 volts.
• The loop status is Closed.
• The secondary air injection (AIR) and the catalyst diagnostics are not active.
• The throttle position (TP) indicated angle is between 3-70 percent more than the value observed at idle.
• The Fuel Trim Learn is enabled.
• The air fuel ratio is between 14.5-14.7 percent.
• The fuel tank level remaining is more than 10 percent.

Conditions for Setting the DTC

• The HO2S signal voltage remains above 775 mV.
• The conditions exist for 31 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.
• Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Important

• Check the HO2S electrical connections for evidence of water intrusion. Water in the connector causes the B+ supply to the heater to bleed into the signal circuit.
• Check the fuel pressure. The system goes rich if the pressure is too high. The PCM compensates for some increase. If the fuel pressure is too high, a DTC may set. Refer to Fuel System Diagnosis .
• Check for rich injectors. Perform the Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool .
• Check for leaking injectors. Refer to the Fuel System Diagnosis .
• Check the evaporative emissions (EVAP) canister purge. Inspect for fuel saturation. If the canister is full of fuel, inspect the canister control and the hoses. Refer to Evaporative Emission (EVAP) Control System Description .
• Check the MAF sensor. Disconnect the MAF sensor and see if the rich condition is corrected. If the condition is corrected, inspect for proper installation. If the MAF sensor is correctly installed, replace it. If the MAF sensor is installed backwards, the system goes rich. The plastic portion of the sensor has arrows that indicate the proper air flow direction. The arrows must point toward the engine.
• Check the oxygen supply inside the HO2S for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and connections for breaks, or for contamination. Refer to Wiring Repairs in Wiring Systems.
• Check for an intermittent condition. Refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.