Diagnostic Notes - Read First

TIP: Verify that the vehicle being tested has a fully charged battery. If it does not, false diagnostic codes or error messages may occur.

CAUTION: Be careful when performing electrical tests to prevent accidental shorting of terminals. Such mistakes can damage fuses or components and will sometimes set a second code, making diagnosis of the original problem more difficult.


To efficiently diagnose CCD bus problems follow these six steps:
1. Verify Complaint
2. Check for Related Symptoms
3. Analyze Symptoms
4. Isolate the Problem
5. Repair the Isolated Problem
6. Verify Proper Operation

ROAD TESTING
Some complaints will require a test drive to duplicate the diagnostic code or symptom condition and to verify the repair.

CAUTIONS:
- Before road testing a vehicle, be sure that all components are reassembled.
- During the test drive, do not try to read the scan tool screen while in motion.
- Do not hang the scan tool from the rear view mirror or operate it yourself. Have an assistant available to operate the scan tool.