Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Powertrain Control Module (PCM) DTCs and Freeze Frame Data and record on the repair order.
2. Using the recorded Freeze Frame Data and the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
3. With the scan tool, read PCM DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K81) INTAKE O2 SENSOR HEATER CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Intake O2 Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K81) Intake O2 Sensor Heater Control circuit at the Intake O2 Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K81) Intake O2 Sensor Heater Control circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (Z909) O2 SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance between ground and the (Z909) O2 Sensor Ground circuit at the Intake O2 Sensor harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (Z909) O2 Sensor Ground circuit for an open circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K81) INTAKE O2 SENSOR HEATER CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K81) Intake O2 Sensor Heater Control circuit between the Intake O2 Sensor harness connector and the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K81) Intake O2 Sensor Heater Control circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE PCM INTAKE O2 SENSOR HEATER CONTROL DRIVER FOR PROPER OPERATION
1. Reconnect the PCM C2 harness connector.
2. Turn the ignition on.
3. With the scan tool, actuate the Intake O2 Sensor control to the maximum allowable percentage.
4. Using a 12-volt test light connected to 12 volts, probe the (K81) Intake O2 Sensor Heater Control circuit in the Intake O2 Sensor harness connector.
  NOTE:
  The test light should be illuminated. The brightness will be dependent on the actuation percentage selected.
5. With the scan tool, actuate the Intake O2 Sensor control to the OFF (0%) position.
6. Using a 12-volt test light connected to 12 volts, check the (K81) Intake O2 Sensor Heater Control circuit in the Intake O2 Sensor 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 (0%)?
  
  Yes
  - Replace the Intake 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 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 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.