Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data and record any DTCs on the repair order.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.
  Did the DTC reset?
  
  Yes
  - Go To 2
  No
  - Perform to the INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any 5-Volt supply DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DTC INDEX .
  No
  - Go To 3
CHECK THE (K648) HUMIDITY SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the engine off.
2. Disconnect the MAF/Intake Air Sensor harness connector.
3. Turn the ignition on, engine off.
4. Measure the voltage on the (K648) Humidity Signal circuit at the MAF/Intake Air Sensor harness connector.
  Is the voltage above 5.2 Volts?
  
  Yes
  - Repair the (K648) Humidity Signal circuit for a short to voltage.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (K648) HUMIDITY CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the engine off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance of the (K648) Humidity Signal circuit between the MAF/Intake Air Sensor harness connector and the PCM C1 harness connector.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (K648) Humidity Signal circuit for an open/high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE MAF/INTAKE AIR SENSOR FOR PROPER OPERATION
1. Replace the MAF/Intake Air Sensor in accordance with the service information. Refer to SENSOR, MASS AIRFLOW (MAF), REMOVAL .
2. Reconnect the MAF/Intake Air Sensor harness connector.
3. Reconnect the PCM C1 harness connector.
4. Turn the ignition on.
5. With the scan tool, erase PCM DTCs.
6. Perform several ignition key cycles leaving the ignition on for at least 10 seconds per cycle.
7. Start the engine and let it run for two minutes.
8. With the scan tool, read PCM DTCs.
  Does the scan tool display this DTC?
  
  Yes
  - Go To 6
  No
  - Test complete.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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
  - Repair the poor connections.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .