Diagnostic Test
- CHECK FOR AN ACTIVE DTC
- Start the engine and allow it to idle for at least 60 seconds. Allow the engine to run long enough for the O2 Sensor to enter closed loop operation.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.
- With the scan tool, read DTCs and record on the repair order.
Is the DTC active or pending?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- Start the engine and allow it to idle for at least 60 seconds. Allow the engine to run long enough for the O2 Sensor to enter closed loop operation.
- CHECK FOR THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO ANOTHER VOLTAGE SUPPLY
- Turn the ignition off.
- Disconnect the Oxygen Sensor 1/2 harness connector.
- Disconnect the PCM C2 harness connector.CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
- Connect the (special tool #10436, Adapter, GPEC Diagnostic).
- Check for continuity between the (K141) O2 Sensor 1/2 Signal circuit and all other 5 volt and 12 volt supply circuits at the GPEC Adaptor.
Is there continuity between the (K141) O2 Sensor 1/2 Signal circuit and any 5 volt and 12 volt supply circuits?
Yes
- Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to the circuit that measured below 10k Ohms.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 3
- CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Check for continuity of the (K141) O2 Sensor 1/2 Signal circuit between the Oxygen Sensor 1/2 harness connector to the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 4
No
- Repair the (K141) O2 Sensor 1/2 Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Check for continuity of the (K141) O2 Sensor 1/2 Signal circuit between the Oxygen Sensor 1/2 harness connector to the GPEC Adaptor.
- CHECK THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Check for continuity of the (K904) O2 Sensor 1/2 Return circuit between the Oxygen Sensor 1/2 harness connector to the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 5
No
- Repair the (K904) O2 Sensor 1/2 Return circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Check for continuity of the (K904) O2 Sensor 1/2 Return circuit between the Oxygen Sensor 1/2 harness connector to the GPEC Adaptor.
- OXYGEN SENSOR 1/2
- Turn the ignition off.
- Reconnect the Powertrain Control Module (PCM) harness connector.
- Connect a jumper between the (K141) O2 Sensor 1/2 Signal circuit and the (K904) O2 Sensor 1/2 Return circuit in the Oxygen Sensor 1/2 harness connector.
- Turn the ignition on.
- With a scan tool, monitor the O2 Sensor 1/2 volts.NOTE:
The sensor should read at or very near zero volts with the jumper in place.
Is the voltage at or very near zero volts with the jumper in place?
Yes
- Replace the Oxygen Sensor 1/2 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 6
- CHECK RELATED PCM AND COMPONENT CONNECTIONS
- Perform any Service Bulletins that apply.
- Disconnect all PCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
- Proper connector installation.
- Damaged connector locks.
- Corrosion.
- Other signs of water intrusion.
- Weather seal damage (if equipped).
- Bent terminals.
- Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
- Terminals that have been pushed back into the connector cavity.
- Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
- Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL AND INSTALLATION .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Test complete.