P0032
P0032-O2 SENSOR 1/1 HEATER CIRCUIT HIGH
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1,000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.
- When Monitored:
Continuously during O2 heater operation with battery voltage between 10.4 and 15.75 Volts.
- Set Condition:
The Powertrain Control Module (PCM) detects that the O2 sensor heater element input is above the maximum acceptable voltage. One trip fault. Three good trips to turn off the MIL.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
NOTE: If any ASD Relay DTCs have set along with any of the O2 SENSOR HEATER CIRCUIT HIGH DTCs, all of the ASD O2 Sensor Heater Feed circuits need to be checked for a short to battery voltage.
1. Start the engine and allow it to idle for at least 60 seconds.
2. With the scan tool, read the active DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. O2 HEATER ELEMENT
1. Turn the ignition off.
NOTE: Allow the O2 Sensor to cool down to room temperature.
2. Disconnect the 1/1 O2 Sensor harness connector.
3. Measure the resistance across the O2 Sensor Heater element between the O2 Heater Control terminal and the O2 Heater ground terminal at the component.
NOTE: O2 Heater Element resistance values should be measured at 21.1° C (70° F). The resistance value will vary with different temperature values.
Is the O2 Sensor Heater Element resistance between 2.0 and 30.0 Ohms?
Yes
- Go To 3
No
- Verify that there is good pin to terminal contact in the 1/1 O2 Sensor and Powertrain Control Module connectors. If OK, replace the O2 Sensor. Oxygen Sensor - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
3. O2 1/1 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the O2 1/1 Heater Control circuit in the 1/2 Oxygen Sensor harness connector.
Is there any voltage present?
Yes
- Repair the short to voltage in the O2 1/1 Heater Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 4
4. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the 1/1 O2 Sensor and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module. PCM/ECM Reprogramming.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.