Diagnostic Test
- ACTIVE DTC
- Ignition on, engine not running.
- With a scan tool, read DTCs.
Is the DTC active at this time?
Yes
- Go to step 2
No
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
- PCV SYSTEM
- Visually and Physically inspect the PCV system.
- Check for the PCV valve disconnected.
- Check for an incorrect PCV valve. The PCV valve must meet OEM specifications.
- Damage vacuum hose.
Were any of the above condition found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
No
- Go to step 3
- IAC MOTOR PASSAGES
- Turn the ignition off.
- Remove the IAC Motor.
- Inspect the IAC Motor and passages for any obstructions or damage to motor.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
No
- Go to step 4
- VACUUM LEAKS
- Start the engine.
- Inspect the vehicle for external vacuum leaks.
- Inspect the engine for internal vacuum leaks.
Were any vacuum leaks found?
Yes
- Repair the vacuum leak as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
No
- Go to step 5
- AIR INDUCTION SYSTEM
- Inspect the Air Induction System for the following problems.
- Restrictions: Dirty Air Cleaner, Foreign material trapped in the air intake tube, etc.
- Leaks: Air Intake tube connection, Air Cleaner housing, etc.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
No
- Go to step 6
- THROTTLE BODY AND THROTTLE LINKAGE
- Inspect the throttle body plate carbon build up or other restrictions.
- Inspect the throttle linkage for binding and smooth operation.
- Ensure the throttle plate is resting on the stop at idle.
Were any problems found?
Yes
- Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
No
- Test Complete.