Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Start the engine and allow it to Idle.
2. 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 .
CHECK THE O2 SENSOR 2/2 (K399) HEATER CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the O2 Sensor 2/2 harness connector.
3. Disconnect the PCM C2 harness connector.
4. Check for continuity between ground and the O2 Sensor 2/2 (K399) Heater Control circuit at the O2 Sensor 2/2 harness connector.
  Is there continuity between ground and the O2 Sensor 2/2 (K399) Heater Control circuit at the O2 Sensor 2/2 harness connector?
  
  Yes
  - Repair the O2 Sensor 2/2 (K399) Heater Control circuit for a short to chassis ground or the O2 Sensor (Z909) Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE O2 SENSOR 2/2 HEATER CONTROL CIRCUIT
1. Turn the ignition off.
2. Reconnect the PCM harness connector.
3. Turn the ignition on.
4. With the scan tool, actuate the O2 Sensor 2/2 control to the maximum allowable percentage.
5. Using a 12-volt test light connected to ground, probe the O2 Sensor 2/2 (K399) Heater Control circuit at the O2 Sensor 2/2 harness connector.
  NOTE:
  The test light should be illuminated. The brightness will be dependent on the actuation percentage selected.
6. With the scan tool, actuate the O2 Sensor 2/2 control to the OFF (0%) position.
7. Using a 12-volt test light connected to ground, probe the O2 Sensor 2/2 (K399) Heater Control circuit at the O2 Sensor 2/2 harness connector.
  NOTE:
  The test light should not be illuminated.
  
  Does the test light illuminate with the actuator ON and not illuminate with the actuator OFF?
  
  Yes
  - Replace the O2 Sensor 2/2 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
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 and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .