BMW E36 Blog

Hi Guys,

I know this is one of the most confusing subjects about the BMW E36 cars. Too many sensors with complicated names. Hopefully, this list will help you figure out what the most common sensors in your cars are and what they actually do. Have fun O_o :-

Symbol	Name	Job	Picture
CPS	Crank Position Sensor	Controls the timing of firing for the spark plugs.
CMP	Camshaft Position Sensor	Controls the timing of injecting fuel.
MAF	Mass Air flow Sensor	Reads the volume of air entering the engine intake.
ICV	Idle Control Value	By controlling how much air is allowed to enter through the throttle plate, it controls the idle of the engine. In many cases where the BMW E36 is not idling perfectly, the Idle control valve is the reason behind this problem. Read about cleaning the ICV.
IAT	Air Intake Temp Sensor	Measures incoming air temperature. If the air is cold (more dense), the engine will need more fuel.
O2	Oxygen Sensor (Precat, Postcat)	Monitors the gas that’s coming out of exhaust and provides readings to the DME to help it mix air+fuel better.
CTS	Coolant Temp Sensor	Measures temperature of the coolant.
TPS	Throttle Position Sensor	Measures changes in the throttle position.

BMW E36 Blog: The ultimate BMW E36 information source.

Hello friends,

I found this article about on board diagnostics for your BMW E36 and I thought wow! that’s cool. Unfortunately, I tried to do it on my BMW E36 1993 318is but it didn’t work 🙁 I’m not sure whether I did it right or not, maybe some of you guys will try it. I think it should work, but in my case, I don’t know why it didn’t. Anyway, I shouldn’t forget to thank Jared Fenton, the author of the article. Ready? here it goes:

Disclaimer: Use it at your own risk !!!

Did you know that your BMW 3 Series has an internal diagnostic program built into the computer? Not many people know about this. On the BMW 3 Series, there is a way that you can diagnose common engine problems without having to purchase a code tool or take it to the dealer to have it scanned. This is one of those neat little features of the Service Indicator Computer; the series of lights directly under the tachometer and speedometer that remind you to change the oil and perform service. In this tech article, I will provide you with the procedure for checking the fault codes and what the codes mean. This guide will help you to diagnose any possible problems with your car.

This article is written for both the BMW E30 and E36 3 Series cars (up to 95) and should work on both models where a Service Indicator Computer is used. I will go over the small differences between the early and late cars, as they differ slightly. Keep in mind that this procedure will not work on early cars with Motronic 1.1.

Now on the E30 models, get in the car and put the key in the ignition and turn it to the second turn or �ON� position, but do not start the car. Now, press the accelerator pedal all the way to the floor, then let it release all the way back. Now repeat the depress/release cycle 4 more times fairly quickly, but not too fast. It may take some time to get this timing down correct. It should only take you a few seconds to do this. What this does is activate the wide-open throttle switch and the idle switch 5 times. This then sends a signal to the Motronic ECU to send fault codes to the Service Indicator Light.

On the E36 models, the procedure works the same way, but the timing at which you press/release the gas pedal is faster than on the E30. Just keep at it, and you will eventually get the correct speed.

Watch the �Check Engine� light. It should blink once, and then start blinking a series of four numbers. For instance, say this is a sequence you see� the light blinks once, then twice, then four times and lastly four times. If you read it correctly this means that the SI light is reading out the code 1244 (faulty camshaft sensor) The codes appear as a series of flashes for each digit. The flashes indicating one digit are about one second apart, the next digit will appear after a couple seconds interval. If there are no faults in the car, the computer will flash out the number 1444.

Here is the list of codes and what they indicate.

1211 DME Control Unit

1215 Air Mass Sensor

1216 Throttle Potentiometer

1218 Output Stage, Group 1

1219 Output Stage, Group 2

1221 Oxygen Sensor 1

1212 Oxygen Sensor 2

1222 Lambda Control 1

1213 Lambda Control 2

1223 Coolant Temperature Sensor

1224 Intake Air Temperature Sensor

1225 Knock Sensor 1

1226 Knock Sensor 2

1227 Knock Sensor 3

1228 Knock Sensor 4

1231 Battery Voltage/DME Main Relay

1232 Throttle Idle Switch

1233 Throttle Wide Open Throttle Switch

1234 Speedometer A Signal

1237 A/C Compressor Cut Off

1242 A/C Compressor

1243 Crankshaft Pulse Sensor

1244 Camshaft Sensor

1245 Intervention AEGS

1247 Ignition Secondary Monitor

1251 Fuel Injector 1 (or group 1)

1252 Fuel Injector 2 (or group 2)

1253 Fuel Injector 3

1254 Fuel Injector 4

1255 Fuel Injector 5

1256 Fuel Injector 6

1257 Fuel Injector 7

1258 Fuel Injector 8

1261 Fuel Pump Relay Control

1262 Idle Speed Actuator

1263 Purge Valve

1264 EGO Heater

1265 Fault Lamp (check engine light)

1266 VANOS

1267 Air Pump Relay Control

1271 Ignition Coil 1

1272 Ignition Coil 2

1273 Ignition Coil 3

1274 Ignition Coil 4

1275 Ignition Coil 5

1276 Ignition Coil 6

1277 Ignition Coil 7

1278 Ignition Coil 8

1281 Control Unit Memory Supply

1282 Fault Code Memory

1283 Fuel Injector Output Stage

1286 Knock Control Test Pulse

1444 No Fault Codes
 

I hope you enjoyed this article and I hope it will work for you.

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Best regards,

Tony Sticks.