The strategy based diagnostic is a uniform approach to repair all Electrical and Electronic (E/E) systems. Resolve an E/E system problem using the diagnostic flow. The diagnostic flow is also a starting point when repairs are necessary. The steps below are defined in order to instruct the technician how to proceed with a diagnosis.

Verify the Customer Complaint

In order to verify the customer complaint the technician should know the normal operation of the system.

Preliminary Checks

Perform the following steps:

1. Conduct a thorough visual inspection
2. Review the service history
3. Detect unusual sounds or odors
4. Gather diagnostic trouble code information in order to achieve an effective repair

Check Bulletins and Other Service Information

This should include videos, newsletters, and Pulsat programs.

Service Information System Checks

A system may not be supported by one or more DTCs. System checks verify the proper operation of the system. This will lead the technician in an organized approach to diagnostics.

Service Diagnostics (Paper and Electronic)

1. DTC Stored - Follow the designated DTC Table exactly to make an effective repair.
2. No DTC - Select the symptom from the symptom tables and follow the diagnostic paths or suggestions to complete the repair, or refer to the applicable component/system check.
3. No Matching Symptom - Analyze the complaint. Develop a plan for diagnostics. Utilize the wiring diagrams and theory of operation.
4. Intermittents - Conditions that are not always present are intermittent. In order to resolve Intermittents, perform the following steps:

4.1.	Observe the history DTCs, the DTC modes and, the freeze frame data.

Call technical assistance for similar cases where repair history may be available. Combine the technician knowledge with efficient use of the available service information.

4.2.	Evaluate the symptoms and conditions described by the customer.

4.3.	Use a check sheet or other method in order to identify the circuit or electrical system component.

4.4.	Follow the suggestions for intermittent diagnosis found in the service documentation.

4.5.	The Tech 1, Tech 2 and Fluke 87 scan tools have data capturing capabilities that can assist in detection of Intermittents.

5. Vehicle operates as designed/No trouble found
6. Call technical assistance for similar cases where repair history may be available. Combine technician knowledge with efficient use of the available service information.

6.1.	This condition exists when the vehicle is found to operate normally.

6.2.	The condition described by the customer may be normal. Verify against another vehicle that is operating normally.

6.3.	The condition may be intermittent. Verify the complaint under the conditions described by the customer before releasing the vehicle.

Re-Examine the Complaint

When the complaint cannot be successfully found or isolated, a reevaluation is necessary. The complaint should be re-verified and could be intermittent or normal.

Repair and Verification Tests

After isolating the cause, the repairs should be made. Then validate for proper operation and verify that the symptom has been corrected. This may involve road testing the vehicle in order to verify that the complaint has been resolved.