Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Start the engine and allow it to reach normal 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 the scan tool, read DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor 1/2 harness connector.
3. 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.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
5. Check for continuity of the (K299) O2 Sensor 1/2 Heater Control circuit between the Oxygen Sensor 1/2 harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (K299) O2 Sensor 1/2 Heater Control circuit for an open circuit or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (Z909) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Check for continuity between Battery Negative (-) and the (Z909) Ground circuit in the O2 Sensor 1/2 harness connector.
  NOTE:
  A good chassis ground can also be used in place of the Battery Negative (-).
  
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (Z909) Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE OXYGEN SENSOR 1/2 OPERATION USING THE SCAN TOOL ACTUATOR
1. Connect the Powertrain Control Module (PCM) C2 harness connector.
2. Turn the ignition on.
3. With the scan tool, actuate the Oxygen Sensor 1/2 control to the maximum allowable percentage.
4. Using a 12-volt test light connected to ground, check the (K299) O2 Sensor 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
  NOTE:
  The test light should flash dimly.
5. With the scan tool, actuate the Oxygen Sensor 1/2 control to the OFF (0%) position.
6. Using a 12-volt test light connected to ground, check the (K299) O2 Sensor 1/2 Heater Control circuit in the Oxygen Sensor 1/2 harness connector.
  NOTE:
  The test light should not be illuminated.
  
  Does the test light flash dimly with the actuator ON (25%) and not illuminated with the actuator OFF (0%)?
  
  Yes
  - Replace the Oxygen Sensor 1/2 in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. 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 .