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CIS Motronic Engine Code 3B

On California models, codes are read by observing the flashing CHECK light on the instrument panel. See Fig 1 . See CIS MOTRONIC ENGINE CODE 3B FAULT CODES table.

On Federal models, retrieving codes requires use of a VAG 1551 tester. See tool manufacturer's instructions.

On Federal and California models, codes must be retrieved before they can be erased, and codes must be erased with VAG 1551 . Follow tool manufacturers instructions and screen prompts.

Fig 1: Reading Diagnostic Codes on California Vehicles
G94367Courtesy of AUDI OF AMERICA, INC.
CIS MOTRONIC ENGINE CODE 3B FAULT CODES

Code Probable Cause
2111 Defective ECU
2112 No RPM Signal From Hall Sensor or Airflow Sensor Plate Not Moving Freely
2121 (1) Defective Idle Switch
2123 Defective Full Throttle Switch
2141 Knock Control At Control Limit
2142 Knock Sensor Signal
2231 (1) Adjustment Limits of Idle Stabilization Exceeded
2232 Airflow Sensor Potentiometer
2312 Coolant Temperature Sensor
2341 O2 Sensor Control At Control Limit
2342 O2 Sensor Control
2343 (1) Adjustment Limits of Fuel Mixture Exceeded (Too Lean)
2344 (1) Adjustment Limits of Fuel Mixture Exceeded (Too Rich)
4431 (1) Idle Stabilizer Valve
4444 (1) No Faults Recognized
0000 End of Fault Output Display
(1) These codes are set in temporary fault memory only.