P0132 or P0152 (W/ Denso HO2S)
CIRCUIT DESCRIPTIONThis diagnostic applies only to vehicles built with Denso heated oxygen sensors. To identity the heated oxygen sensor refer to Delphi/Denso Sensor in Computers and Control Systems Component Views.
The Powertrain Control Module (PCM) supplies a voltage of about 450 mV between the Heated Oxygen Sensor (HO2S) high and low signal circuits. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.
The PCM monitors and stores the 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 Diagnostic Trouble Code (DTC) sets.
CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0200, P0300, P0401, P0404, P0405, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1404, P1415, P1416, P1514, P1515, P1516, P1517, or P1518 are not set.
^ The air fuel ratio is between 14.5:1 and 14.7:1.
^ Vehicles without Throttle-actuated Control (TAC), the Throttle Position (TP) is between 3-70 percent.
^ Vehicles with Throttle-actuated Control (TAC), the Throttle Position (TP) indicated angle is between 3-70 percent more than the value observed at idle.
^ The loop status is closed.
^ The ignition 1 signal is between 9-18 volts.
^ The fuel tank level remaining is more than 10 percent.
^ Intrusive tests are not in progress.
^ The scan tool output controls are not active.
CONDITIONS FOR SETTING THE DTC
The HO2S voltage is more than 775 mV for 165 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
IMPORTANT: Never solder the HO2S wires. For proper wire and connector repair, refer to Wiring Repairs or Connector Repairs in Diagrams.
Check the following items:
^ Check the fuel pressure. If the pressure is too high, the system will run rich. The PCM can compensate for some increase but if the pressure becomes too high, this DTC may set. Refer to Fuel System Diagnosis. Component Tests and General Diagnostics
^ Check for rich fuel injectors. Perform the Fuel Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2. Component Tests and General Diagnostics
^ Check for a leaking fuel injector. Refer to Fuel System Diagnosis. Component Tests and General Diagnostics
^ Check for fuel contamination of the engine oil.
^ Check the EVAP canister purge. Check for fuel saturation. If full of fuel, check the canister control and the hoses. Refer to Evaporative Emission (EVAP) Control System Description.
^ Check for a leaking fuel pressure regulator diaphragm by checking the vacuum line to the regulator for fuel.
^ Check the TP sensor. An intermittent TP sensor output causes the system to run rich due to a false indication of the throttle moving.
^ Check for a false rich indication due to silicon contamination of the heated oxygen sensor. This DTC, accompanied by a lean driveability condition and a powdery white deposit on the sensor, may indicate a false rich condition.
An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation
Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent and Poor Connections in Diagrams.
If a repair is necessary, then refer to Wiring Repairs or Connector Repairs in Diagrams.
TEST DESCRIPTION
Steps 1-3:
Steps 4-11:
The numbers below refer to the step numbers on the diagnostic table.
5. Monitor the HO2S voltage of the opposite bank sensor. If the voltage activity of the opposite bank sensor is similar to the voltage activity of the suspect sensor, check for rich conditions that would affect both cylinder banks. An opposite bank sensor with normal HO2S voltage activity indicates the suspect HO2S is defective or a rich condition exists only on the suspect HO2S cylinder bank.
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 unapproved silicon RTV engine gasket material or the use of silicon based sprays or fluids within the engine. If the cause of this contamination is not corrected, the replacement HO2S will also get contaminated.