Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
3. Start the engine and test drive the vehicle long enough for the O2 Sensor to enter closed loop operation.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor 1/2 harness connector.
3. Disconnect the PCM C2 harness connector.
4. Check for continuity between ground and the (K141) O2 Sensor 1/2 Signal circuit in the Oxygen Sensor 1/2 harness connector.
  Is there continuity between ground and the (K141) O2 Sensor 1/2 Signal circuit?
  
  Yes
  - Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK FOR THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT
1. Check for continuity 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.
  Is there continuity between (K141) O2 Sensor 1/2 Signal circuit and the (K904) O2 Sensor 1/2 Return circuit?
  
  Yes
  - Repair the short between the (K904) O2 Sensor 1/2 Return circuit and the (K141) O2 Sensor 1/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK FOR THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE (Z909) GROUND CIRCUIT
1. Check for continuity between the (K141) O2 Sensor 1/2 Signal circuit and the (Z909) Ground circuit in the Oxygen Sensor 1/2 harness connector.
  Is there continuity between (K141) O2 Sensor 1/2 Signal circuit and the (Z909) Ground circuit in the Oxygen Sensor 1/2 harness connector?
  
  Yes
  - Repair the short between the (Z909) Ground circuit and the (K141) O2 Sensor 1/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
O2 SENSOR 1/2
1. Reconnect the Oxygen Sensor 1/2 harness connector.
2. Reconnect the PCM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool erase DTCs.
5. Turn the ignition off.
6. Disconnect the Oxygen Sensor 1/2 harness connector.
7. Connect a jumper between the (K141) O2 Sensor 1/2 Signal circuit and the (Z909) Ground circuit.
8. Start the engine and allow it to idle.
9. With the scan tool, read DTCs and record on the repair order.
  Does the P0138-O2 SENSOR 1/2 CIRCUIT HIGH DTC become active or pending with the jumper in place?
  
  Yes
  - Replace the O2 Sensor 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
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.
  Is the DTC active or pending?
  
  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.