Diagnostic Test

OXYGEN SENSOR 1/1 VOLTAGE
1. Start the engine and allow it to reach operating temperature.
  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.
2. With a scan tool, monitor the 1/1 O2 Sensor volts.
  Is the voltage greater than 3.9 volts?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K41) O2 1/1 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor 1/1 harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (K41) O2 1/1 Signal circuit in the Oxygen Sensor 1/1 harness connector.
  NOTE:
  Measure the voltage in reference to ground, not the (K902) O2 1/1 Return circuit.
  
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K41) O2 1/1 Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (K902) O2 1/1 RETURN CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (K902) O2 1/1 Return circuit in the Oxygen Sensor 1/1 harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K902) O2 1/1 Return circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK FOR THE (K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO THE (K79) O2 1/1 HEATER CONTROL CIRCUIT
1. Turn the ignition off.
2. Check for continuity between the (K41) O2 1/1 Signal circuit and the (K79) O2 1/1 Heater Control circuit the Oxygen Sensor 1/1 harness connector.
  Is there continuity between the (K41) O2 1/1 Signal circuit and the (K79) O2 1/1 Heater Control circuit?
  
  Yes
  - Repair the (K41) O2 1/1 Signal circuit for a short to the (K79) O2 1/1 Heater Control circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
OXYGEN SENSOR 1/1
1. Reconnect the PCM C2 harness connector.
2. Connect a jumper between the (K41) O2 1/1 Signal circuit and the (K902) O2 1/1 Return circuit in the Oxygen Sensor 1/1 harness connector.
3. Turn the ignition on.
4. With a scan tool, monitor the O2 Sensor 1/1 volts.
  Is the voltage between 2.3 and 2.7 volts with the jumper in place?
  
  Yes
  - Replace the Oxygen Sensor 1/1 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 THE (K41) O2 1/1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. If necessary, remove the jumper wire from between the (K41) O2 1/1 Signal circuit and the (K902) O2 1/1 Return circuit in the Oxygen Sensor 1/1 harness connector.
2. 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.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
4. Measure the resistance of the (K41) O2 1/1 Signal circuit between the Oxygen Sensor 1/1 harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (K41) O2 1/1 Signal circuit for an open circuit or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K902) O2 1/1 RETURN CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (K902) O2 1/1 Return circuit between the Oxygen Sensor 1/1 harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 8
  No
  - Repair the (K902) O2 1/1 Return circuit for an open circuit or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Powertrain Control Module 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.