Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Body Diagnostic Procedures: Introduction: Notes
The procedures contained in this article include all the specifications, instructions, and graphics needed to diagnose 2003 body system problems. The diagnostics in this article are based on the failure condition or symptom being present at time of diagnosis.
Please follow the recommendations below when choosing your diagnostic path.
- First make sure the DRBIII(R) is communicating with the appropriate modules; i.e., if the DRBIII(R) displays a "No Response" or "Bus +/-signal open" condition, you must diagnose that first.
- Read DTC's (diagnostic trouble codes) with the DRBIII(R).
- If no DTC's are present, identify the customer complaint.
- Once the DTC or customer complaint is identified, locate the matching test in the Table of Contents and begin to diagnose the symptom.
An * placed before the symptom description indicates a customer complaint.
When repairs are required, refer to the appropriate service procedures for the proper removal and repair.
Diagnostic procedures change every year. New diagnostic systems may be added; carryover systems may be enhanced. READ THIS BEFORE TRYING TO DIAGNOSE A VEHICLE DIAGNOSTIC TROUBLE CODE. It is recommended that you review the entire article to become familiar with all new and changed diagnostic procedures.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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