LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Audi >> 1987 >> 5000 CS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> BOSCH Cis-E III System >> Testing >> Trouble Codes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Trouble Codes

  1. Drive vehicle for a minimum of 5 minutes to allow fault information to be stored. If it is a no-start condition, operate starter for at least 6 seconds.
    CAUTION: DO NOT turn ignition off. This will erase the fault memory.
    Fig 1: Location of Fuel Pump Relay
    G61291
  2. Insert fuse into fuel pump relay for at least 4 seconds. See Fig 1 . Indicator light on instrument cluster should display a 4-digit fault code from the ICU.
  3. If indicator light displays a Code 4444, no faults have been recorded. Record all fault codes by repeating step 2) until a Code 0000 is displayed. This indicates that all fault codes from the ICU have been displayed.
  4. Repeat step 2) after the Code 0000 is displayed. This time, however, the faults that are displayed will be from the FICU. Engine speed may increase. Record all codes.
  5. Repeat step 2) until all FICU fault codes have been displayed. When all fault codes from the FICU have been displayed, a Code 0000 will display.
  6. For a list of all ICU and FICU fault codes, refer to SELF-DIAGNOSTIC FAULT CODES  chart.
SELF-DIAGNOSTIC FAULT CODES

Code Location Of Fault Problem
1111 Ignition control unit or fuel injection control unit Defective memory circuits in control unit
2121 Idle switch Switch stuck closed or problem in wiring to switch
2122 Engine speed signal or Hall sender No engine speed signal from Terminal #17 of ignition control unit to Terminal #30 of fuel injection control unit
2123 Full throttle switch Switch stuck closed or problem in wiring to switch
2141 Knock regulation Engine or ignition knock is causing timing to be retarded the maximum amount
2142 Knock sensor Defective sensor or sensor wiring
2223 Altitude sensor No signal from sensor
2232 Air sensor potentiometer No signal from potentiometer to fuel injection control unit or break in wire between fuel injection control unit Terminal #21 and ignition control unit Terminal #8
2233 Reference (supply) voltage for air sensor potentiometer and altitude sensor No reference voltage from Terminal #21 of ignition control unit to Terminal #26 of fuel injection control unit
2312 Coolant temperature sensor No signal from sensor
2341 Oxygen sensor control Oxygen sensor control operating at rich or lean limit
2342 Oxygen sensor No signal from sensor
4431 Idle stabilizer valve problem Problem in wiring to idle stabilizer valve
4444 No faults stored in memory N/A
0000 End of Diagnosis N/A
Fig 2: Version One Ignition Coil & Power Stage
G61293
Fig 3: Version 2 Ignition Coil & Power Stage
G61292