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.
Notes
ECM Coding Variation: Notes — 1994 Audi S4 Service Manual : Notes If Motronic Engine Control Module (ECM) is replaced it is necessary to code new ECM. The coding connector is located in the electronics box. When checking DTC memory, ECM identification and coding are displayed. See RETRIEVING DIAGNOSTIC TROUBLE CODES. Coding is accomplished in the connector by appropriate assignment of terminals 1, 2, 3 and 4. Terminal assignment is stamped on the outside of the connector. Currently, only codes 1 and 4 are available. If the correct coding is not displayed. Check wiring connection for coding connector. See CHECKING CODING CONNECTOR WIRING. CODING 1: This coding does not contain a speed limit. When this coding is present, all of the connector terminals are open. CODING 4: The speed limit with this coding is limited to 130 mph. With code 4, terminal 1 is internally bridged to terminal 4 which results in terminal No. 38 of the Motronic Engine Control Module (ECM) -J220- being connected to ground. ECM CODING OPTIONS Code Options (1) Application Coding (1) Valid For European Countries Coding (4) Valid For U.S. & Canada (1) WARNING! When the coding connector is disconnected, code (4) becomes code (1) which in turn removes the speed limiter. This change is only permissible where legally permitted and must be accompanied by an appropriate set of tires that meet the higher speed rating.
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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.