Diagnostic Test

1. Verification of complaint.
2. Verification of any related symptoms.
3. Symptom analysis.
4. Problem isolation.
5. Repair of isolated problem.
6. Verification of proper operation.

1. Verify there are no outward signs of vehicle damage that could impact the proper operation of the theft or security system. Check for aftermarket vehicle accessories that may have been installed improperly or could interfere with the system
2. Check the vehicle repair history for repairs that may relate to the current condition.
3. Perform a check of current Technical Service Bulletins (TSB) for the Theft/Security system related to the customer concern. If a TSB applies, follow the procedure outlined in the TSB.

• Check the control module central to the subsystem that is exhibiting the condition for active DTCs
• For an intermittent failure that is not current at the time of vehicle inspection, refer to the THEFT AND SECURITY SYSTEM INTERMITTENT TEST and document the event on the repair order. Refer to STANDARD PROCEDURE .

As a general rule, for any theft/security system control module that exhibits more than one active DTC, address the codes in the order indicated:

1. Low/High Voltage and Serial Data Loss of Communication Codes
2. Module Internal Failure and Configuration Mismatch Codes
3. Circuit specific DTC failures

Should the malfunction still be present after conducting this Pre-diagnostic Procedure, technicians should continue to the appropriate DTC procedure or symptom diagnostic.

For DTC Procedures, Refer to DIAGNOSIS AND TESTING  and perform the appropriate Diagnostic Procedure.

For Symptom Diagnostics, Refer to DIAGNOSIS AND TESTING .