This page applies to VR6 Motronic OBD1 systems on engine-swapped Mk2s, Corrados, and early Passats (to 1995).

To access the fault system, place an LED test light between the red wire on the black connector and the yellow/black wire on the blue connector under the shift boot. Then turn the ignition on (but don't start the car) and place a jumper between the brown wire on the black connector and the yellow wire on the white connector for at least 5 seconds. Remove the jumper, and the CHECK light on the dashboard should flash one long pulse, then several shorter pulses (with spaces) indicating codes. Please click here for an example.

The example picture above would indicate a 1234 code. Connect the jumper again for at least 4 seconds to advance to the next code. When "0000" (2.5s flashes at 2.5s intervals) or "4444" is read, the sequence is completed. To clear the codes, connect the jumper with the ignition off, then turn it on. After 5 seconds, remove the jumper, and "4444" should be read.
Code Description Action
4444 No faults recorded -
1231 Speed sender Faulty speed sender, bad speedometer cable, or bad cluster fuse
2111 Engine speed sensor Sensor malfunctioning, sensor wheel for engine speed sensor malfunctioning or loose, wiring fault
2113 Camshaft position sensor Rotor twisted, Defective sensor or wiring
2212 Throttle Position Sensor Defective potentiometer or wiring
2312 Coolant temperature sensor Defective coolant temperature sensor or wiring
2142 Knock sensor I Defective knock sensor or wiring. Control unit not recognizing knock signal
2342 Oxygen sensor system (faulty signal or exceeding adjustment range) Faulty sensor wiring, faulty sensor, incorrect idle speed, leaking cold start valve, or intake air leaks
2412 Intake air temperature sensor Sensor malfunctioning, wiring fault
2234 Supply voltage too high or low Battery voltage above/below 16/10v
2231 Idle speed stabilizer has exceeded adaptive range Throttle valve adjustment incorrect, incorrect timing, evap system faulty, or intake air leaks
2141 Knock sensor I Engine knock due to incorrect fuel, incorrect timing, or faulty sensor
2341 Oxygen sensor control exceeded Probe defective, intake air leaks, injectors malfunctioning, fuel pressure low/high, hot wire for MAF not burning cleanly, evap system fault
2144 Knock sensor II Faulty sensor wiring, faulty sensor, or faulty control unit
2214 Maximum engine speed exceeded ECU fault causes over-revving, bad shifting, signal from engine speed sensor defective
2314 Engine/transmission electrical connection Shorted to ground
2324 Mass airflow sensor Signal high/low, sensor malfunctioning, short to positive/ground, air leak
2413 Mixture adaption limit exceeded Fuel pressure fault, misfire, air leaks, injectors leaking, hot wire not burning off cleanly, Oxygen sensor regulation faulty, exhaust leak, evap fault
2411 EGR system (California only) Intake air temperature sensor faulty, faulty EGR sensor wiring, faulty or plugged EGR system
4332 Output stages in engine control module, mechanical malfunction Loose terminal to one of the Output DTM components or to the Motronic engine control module
4343 EVAP canister purge regulator valve Malfunction in wiring, short to positive/negative
4411 Fuel injector #1 fault Check fuel injector wiring
4412 Fuel injector #2 fault Check fuel injector wiring
4413 Fuel injector #3 fault Check fuel injector wiring
4414 Fuel injector #4 fault Check fuel injector wiring
4421 Fuel injector #5 fault Check fuel injector wiring
4422 Fuel injector #6 fault Check fuel injector wiring
4431 Idle stabilizer valve Faulty wiring or valve, or control unit
4433 Fuel pump relay Malfunction or wire has short to positive
4312 EGR vacuum regulator solenoid valve EGR valve malfunction, wiring shorted to ground/positive
1111 Control unit Defective control unit