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.
1987 Audi 5000 CS, AutomaticFACTORY OEM SERVICE PROCEDURE
All Models
- Item Being Tested - Brake Light Switch Depress brake pedal. Voltage reading on ABS tester should be 10.3-14.5 volts. If reading is incorrect, check plug connector for brake light switch.
- Disconnect plug connector for brake light switch and install a jumper wire across connector. Repeat step 1). If voltage reading is now correct, replace brake light switch.
- If reading is still incorrect, check wires to brake light switch for voltage and terminal No. 25 in ABS control unit for continuity. See Figure . Turn ignition off before disconnecting control unit. If wires are okay, replace ABS control unit.
Factory Service Tools
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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.