coolant temerature sensor

[89 e30]

My e30 m20 showed a fault code that my coolant temperature sensor is bad so I changed it out and my engine light is still on and showing me the same code

[jlevie]

There are two temp sensors in the thermostat housing of a 325i/is/ic and four in the housing of a 325e. Which did you change?

The Engine Coolant Temperature (ECT) sensor in an M20 should be the lowest one in the thermostat housing and usually has a blue housing.

[89 e30]

I have a 325is and I changed the lower one

[jlevie]

That should have been the right sensor, if the car was in stock configuration.

Did it have a blue housing and two pins?

This was a 1223 code, right? Does the resistance as measured at the DME connector agree with the resistance as measured at the sensor? A common problem in an 9/87 or later 325i is a bad connection at C191 (located just below the intake manifold). If not the problem is in the engine wiring harness. If so the problem is in the DME.

[89 e30]

Yea its blue with two pins and yes its the 1223 code. I havnt checked the resistance yet, maybe that's the problem:???:

[FLG]

Try removing battery power for a bit, it should reset the DME and if the problem is fixed it wont come back.

[89 e30]

I allready tried that, I removed the battery cable over night this morning it ran like shit and the engin light was still on giving me the 1223 code. It wouldn't even start start this morning it cranked tho..I think thats because the ecu needs a bit to reprogram again

[steinbachphoto]

I allready tried that, I removed the battery cable over night this morning it ran like shit and the engin light was still on giving me the 1223 code. It wouldn't even start start this morning it cranked tho..I think thats because the ecu needs a bit to reprogram again

engine ran like crap most likely because the ecu is re learning and adjusting your afr (i think)