Diagnostic Procedures
- Did you perform the Inspection/Maintenance (I/M) system check? If yes, go to next step. If no, go to INSPECTION/MAINTENANCE SYSTEM CHECK .
- Preprogram the scan tool with the vehicle information before the ignition switch is turned to RUN position. Ensure the vehicle is within the Conditions for Running Test (Cold Start). See CONDITIONS FOR RUNNING TEST (COLD START) . Turn OFF all of the accessories, e.g., A/C, blower fan, etc. Set vehicle parking brake. Verify the transmission is in Park (A/T) or Neutral (M/T). Start engine and allow engine to idle for 2 minutes. When complete, go to next step.
- In order for the next group of tests to run, the vehicle must operate in the following conditions:
- Accelerate at part throttle to 55 MPH. Maintain this speed without changing throttle position for up to 10 minutes until engine reaches operating temperature.
- Continue operating under these conditions for additional 6 minutes.
When complete, go to next step.
- In order for the next group of tests to run, the vehicle must operate in the following conditions:
- Accelerate at part throttle to 47-55 MPH and maintain this speed for 2 minutes, then decelerate to zero MPH.
- With engine idling for 2 minutes, the following criteria should be maintained: Service brake depressed, transmission in Drive (A/T) or Neutral (M/T) with clutch pedal depressed.
When complete, go to next step.
- Using a scan tool, observe the I/M system Status display. Did all of the I/M system Status indicators update to YES? If yes, go to next step. If no, go to the I/M system Set Procedure for the indicated systems.
- Using scan tool, observe emission related DTC portion of I/M system status display. Does the scan tool indicate any emission related DTCs set? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay at this time.
NOTE:
Whenever ignition switch is turned to RUN position, ignition positive voltage is supplied to HO2S heaters. After verifying the enable criteria, Turn ignition off for about 5 minutes to allow the sensors to cool before continuing with the test. Once engine is started, DO NOT turn engine OFF for the remaining portion of the set procedure.
WARNING:
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.