This may be useful to anyone who has a Thema with the Motronic M1.7 system.
To access the diagnostics, switch on the ignition & press the accelerator pedal to the floor 5 times quickly without starting the engine. The engine management light on the dash will flash.
Codes as follows:
4-4-4-4 No error code stored
1-2-1-1 Incorrect battery voltage
1-2-1-4 Engine temperature sensor faulty
1-2-1-6 Throttle angle sensor faulty
1-2-2-1 Air flow meter faulty
1-2-2-2 Constant idle speed actuator faulty (opening winding)
1-2-2-3 Lambda probe regulation faulty
1-2-2-4 Heated lambda probe faulty
1-2-2-5 Air temperature sensor faulty
1-2-2-6 ECU faulty
1-2-3-1 Electroinjectors faulty
1-2-3-2 Ditto
1-2-3-3 Constant idle speed actuator faulty (closing winding)
1-2-3-5 A/c Input signal faulty
1-2-3-6 Heater/ventilation system (compressor control faulty)
1-2-4-3 Petrol pump relay faulty
1-2-4-4 Evaperative solenoid valve faulty
1-2-5-1 Eprom control unit faulty
1-2-5-2 Speed sensor faulty
1-2-5-4 Throttle angle sensor faulty (don't why 2 codes for this)
1-2-5-5- Cam angle sensor faulty
2-1-1-1 Knock sensor 1 faulty
2-1-1-2 Knock sensor 2 faulty
2-1-1-3 Knock regulator faulty (voltage regulator)
2-1-1-6 Ditto
Treat all these codes with caution, it is possible to get codes that end up with you going on a wild goose chase but I have to say they have treated me well.
