1988 Audi 5000 CS, StandardFACTORY OEM SERVICE PROCEDURE

Idle Stabilizer Valve

  1. Turn ignition off. Insert fuse into fuel pump relay. Turn ignition on. Remove fuse for 4 seconds. Reinstall fuse for 4 seconds, then remove fuse. Indicator light should display Code 4443.
  2. Close full throttle switch. Idle stabilizer valve should cycle (click sound) when switch is closed. If no click sound is heard, disconnect idle stabilizer valve connector.
  3. Connect LED Tester (US 1115 ) between terminals No. 1 and No. 2 using jumper wire. LED tester should light up. If tester does light up, replace idle stabilizer valve. If tester does not light up, connect multimeter between connector terminal No. 2 and ground.
  4. Multimeter should read 12 volts. If 12 volts are not present, repair break in wiring. If 12 volts are present, turn ignition off. Remove FICU access cover and disconnect connector.
  5. Connect multimeter between terminal No. 1 of idle stabilizer valve and terminal No. 17 of FICU connector and check for continuity. Multimeter should read .2 ohm. If reading is not to specification, repair break in wiring. If reading is to specification, replace FICU.
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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.