Diagnostic Procedures

Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.

NOTE: Preprogram scan tool with vehicle information before ignition is turned on and vehicle is within conditions for running DTC. See CONDITIONS FOR RUNNING DTC .

Turn off all accessories (e.g. A/C, blower fan, etc.). Set vehicle parking brake. Ensure transmission is in Park (A/T) or Neutral (M/T). Start engine. Allow engine to idle for 2 minutes or until engine reaches normal operating temperature of at least 158°F (70°C).
- Accelerate vehicle at part throttle to 30-50 MPH.
- Maintain speed for 2 minutes or until I/M system status indicator updates to YES.
After completing actions, go to next step.

CAUTION: Road test vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.

- Accelerate vehicle at part throttle to 45-60 MPH.
- Maintain this speed without changing throttle position for 2-3 minutes or until I/M system status updates to YES.
After completing actions, go to next step.
In order for this test to run, vehicle must operate in the following conditions, then go to next step:
- Accelerate vehicle at part throttle to 30-40 MPH.
- Maintain this speed without changing throttle position for 3 minutes.
Accelerate vehicle at part throttle to 50-60 MPH and maintain speed for 3-5 minutes or until I/M system status indicator updates to YES, then go to next step.
In order for this test to run, vehicle must operate in the following conditions:
- Operate engine at idle until it reaches operating temperature of at least 158°F (70°C).
- Accelerate vehicle at part throttle to 35-55 MPH.
- Operate vehicle for 20 minutes at speeds of 35 MPH or more.
- Operate vehicle for 3 minutes at 30-50 MPH with throttle position steady.
Using scan tool, observe I/M system status display. If status displays YES, go to next step.
Using scan tool, observe I/M system status display. If all I/M system status indicators update to YES, go to next step. If not all I/M system status indicators update to YES, go to I/M system set procedure for the indicated systems.
Using scan tool, observe emission related DTC portion of I/M system status display. If scan tool indicates any emission related DTCs, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If scan tool does not indicate emission related DTCs, system is okay.