For related information, see:
Early systems (Motronic 1.1 only, I think) flash the fault codes automatically. If the check engine light comes on, leave the key in the On position, but dont start the car. The light will begin to flash the code after about 3 seconds. Each flash is separated by about 1 second. There arent many codes on this system
1 flash......Air flow sensor malfunction.
2 flashes....Oxygen sensor malfunction.
3 flashes....Coolant Temp. malfunction.
4 flashes....Throttle switch malfunction.
More detail on these early systems can be found in the Bentley manuals.
Late 1980's systems. Motronic 1.3
The fault codes for these systems will appear on the check engine light when you turn the ignition key to the On position (but dont start it), then: fully depress the accelerator pedal, then fully release it. Repeat the depress,release cycle 5 times fairly quickly, but not too fast. It should be completed in a few seconds. What you are doing here is clicking the wide open throttle switch then the idle switch each 5 times. This signals the Motronic unit to send the fault codes by flashing the light. You should see the light flash once then it will start flashing the 4 digit codes. If there are no faults, you should see the 1444 code (and 2444 if you have a 12 cylinder). The codes appear as a series of flashes for each digit. The flashes indicating one digit are about 1 second apart, the next digit appears after a couple second interval. The rest of the fault codes appear in Table 1 below.
The later systems up to ~ 1995 (Motronic 3.x)
The fault codes appear in the same way as for the Motronic 1.x systems listed above, but it is much trickier to get them to appear. The timing with which you turn the key then depress and release the accelerator pedal is much more critical. You have to depress and release the pedal 5 times, rhythmically, but much faster than for the earlier system. It usually takes a few tries to get it right.
The very latest systems (1995 on)
Fault codes are not available through the check engine light.
This table lists all the fault codes we could find. If anyone has others, please send them to us. The faults listed are for all different models and some of them are not applicable like Fuel Injector 8 on a 6 cylinder car.
|DME Control Unit||1211|
|Air Mass/Volume Sensor||1215|
|Output Stage, Group 1||1218|
|Output Stage, Group 2||1219|
|EGO(O2) Sensor 1||1221|
|EGO(O2) Sensor 2||1212|
|Lambda Control 1||1222|
|Lambda Control 2||1213|
|Coolant Temp. Sensor||1223|
|Intake Air Temp. Sensor||1224|
|Knock Sensor 1||1225|
|Knock Sensor 2||1226|
|Knock Sensor 3||1227|
|Knock Sensor 4||1228|
|Battery Voltage/DME Main Relay||1231|
|Throttle Idle Switch||1232|
|Throttle WOT Switch||1233|
|Speedometer A Signal||1234|
|A/C Compressor cut off||1237|
|Crankshaft Pulse Sensor||1243|
|Ignition Secondary Monitor||1247|
|Fuel Injector 1 (or group 1)||1251|
|Fuel Injector 2 (or group 2)||1252|
|Fuel Injector 3||1253|
|Fuel Injector 4||1254|
|Fuel Injector 5||1255|
|Fuel Injector 6||1256|
|Fuel Injector 7||1257|
|Fuel Injector 8||1258|
|Fuel Pump Relay Control||1261|
|Idle Speed Actuator||1262|
|Fault Lamp (check engine)||1265|
|Air Pump Relay Control||1267|
|Ignition Coil 1||1271|
|Ignition Coil 2||1272|
|Ignition Coil 3||1273|
|Ignition Coil 4||1274|
|Ignition Coil 5||1275|
|Ignition Coil 6||1276|
|Ignition Coil 7||1277|
|Ignition Coil 8||1278|
|Control Unit Memory Supply||1281|
|Fault Code Memory||1282|
|Fuel Injector Output Stage||1283|
|Knock Control test Pulse||1286|
|Model Year.||Body Style.||Model.||Processor type.||EPROM type.|
|9/84 - 9/87||E30||325e/es||1802||2732A|