Diagnostic Procedures

Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.

NOTE: Once engine is started, DO NOT turn engine off for the remainder of the procedure or until test is complete.

- Start and operate engine at idle.
- Ensure vehicle is within the conditions for running DTC. See CONDITIONS FOR RUNNING DTC .
- Set vehicle parking brake.
- Place transmission in Park (A/T) or Neutral (M/T).
- Turn off all of accessories (e.g., A/C, blower fan, etc.).
- Operate engine at idle until it reaches operating temperature of at least 158°F (70°C).
- Accelerate vehicle at part throttle to 45 MPH.
- Accelerate vehicle at part throttle to 30-50 MPH.
- Observe scan tool until I/M System Status indicator updates to YES.
If status updates to YES within 2 minutes, go to step 5 . If status does not update to YES within 2 minutes, go to next step.
Using scan tool, observe DTC information. If scan tool indicates any failed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If scan tool does not indicate any failed DTCs, go next step.

NOTE: Refer to INSPECTION/MAINTENANCE COMPLETE SYSTEM SET PROCEDURE to determine which DTCs are required to run in order to complete this test.

Operate vehicle within Conditions For Running DTC. See CONDITIONS FOR RUNNING DTC . Repeat procedure until scan tool indicates that diagnostic test has run. Using scan tool, observe I/M System Status display. If status updates to YES, go to next step. If status does not update to YES, go to DIAGNOSTIC AIDS .
Using scan tool, observe emission related DTC portion of I/M System Status display. If scan tool indicates any emission related DTCs are set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, system is okay.