Diagnostic Strategy

DIAGNOSTIC STRATEGY

Always begin diagnosis with the Diagnostic system check chart. This chart will help confirm the customer complaint and will identify the proper diagnostic chart for that system.

Don't go directly to one of the trouble charts without performing the diagnostic system check. Replacement of good parts could result.

As indicated in the diagnostic system check, it is important to determine if there are any engine or body codes. If any codes are indicated, refer to the proper section on computerized engine controls.

After any system repair, it is important to return to the diagnostic system check and look for further problems. If none are found, complete the PASSkey(R) system verification.

At the beginning of diagnosis, it is important to observe the security indicator lamp when starting the vehicle's engine. Notice that this is an integral part of the diagnostic system check. Based on whether the engine cranks and/or starts and the function of the indicator lamp, proceed with diagnosis. Remember that the engine may fail to start of crank for reasons other than failure of the PASSkey(R) system.



VISUAL INSPECTION

Several quick visual checks can save you time during diagnosis.

1. Inspect the key. If the coded resistor is dirty or missing, the engine will not start.
2. Look inside the lock cylinder. Dirty or damaged pellet contacts can also disable starting.
3. Check the appropriate fuses.
4. Verify all system power and ground connections.