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.
1988 Audi 5000 CS, StandardFACTORY OEM SERVICE PROCEDURE
Idle Stabilization (Shift Mode Signal)
- Turn ignition off. Disconnect FICU harness connector. Connect LED Tester (US 1115 ) between terminals No. 14 and No. 34 of FICU connector. Turn ignition on.
- Vehicles with automatic transmission, engage selector lever in "N" and then "P". Tester must illuminate. Tester should not illuminate when shifted into driving gears. If light does not illuminate as specified, repair break in wiring.
- Vehicles with manual transmission, shift into any gear. Tester must illuminate. If tester does not illuminate, repair break in wiring.
Factory Service Tools
Use the Manual With the Right Hardware
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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.