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.
1994 Audi S4FACTORY OEM SERVICE PROCEDURE
MOTRONIC Engine Control Module: Notes
NOTE:
When Motronic Engine Control Module (ECM) connectors are disconnected, all Diagnostic Trouble Codes (DTCs) will be erased. ONLY disconnect or reconnect ECM wiring harness connectors with ignition switch in the OFF position. WAIT at least 20 seconds before disconnecting ECM. Failure to do so may damage the ECM.
Factory Service Tools
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.