Crank position sensor signal valve (M104.980)

[herrickmky]

I kept getting cps error from X14 pin 8 as follows:


After I installed 2 new CPS, the same fault code still appears

Hence, I measured if the ECU is receiving signal from the crankshaft position sensor. I disconnected the ECU and had the car started, then measured the voltage between pin 27 and ground. The result is as shown in the following Youtube video. Seems that there is signal from the CPS, what I want to verify is if the value is right. FYI, rpm is constantly dropping during the process

CPS signal to ECU

Any thought is welcome

Cheers!

 

[ray_hennig]

I think we have met on the US board.

My answer is the same. I believe this error to be a red herring. It returns an error because the sensor is sensing nothing as the engine is not turning. If the sensor returns nothing, the system might assume that the sensor is faulty.

I have had that error, with 2 or 3 different sensors, since I built my LED code reader - 15+ years? And I have no reason to believe any of the sensors are faulty. And the car is running like new - touch wood.

These sensors are very simple so it's just a question of ensuring that it's properly installed and that the wiring and connector to the EZL are in good condition.

What symptoms are you having with your car? Is there a problem that you are investigating by reading codes? Are there any other error codes?

Good hunting.

RayH

 

[grober]

WHAT TYPE OF ECU DOES THE CAR HAVE?-----EZL? Symptoms indicate a possible an ecu internal heat buildup leading to a leakage to earth.
have you checked your engine earth strap connections for corrosion / breakage? Can cause strange electrical symptoms

 

[ray_hennig]

WHAT TYPE OF ECU DOES THE CAR HAVE?-----EZL?

Yes. The title of the thread confirms he has the 104.980 engine, just as I do. With the Bosch Ke-Jetronic injection with separate distributor ignition. The only electronics under threat of heat is the EZL.

I think he's worrying about nothing unless he responds with clear symptoms of a problem. As said, I've had that error for decades with several CPSs and several EZLs.

But I agree with you in cleaning all electrical connections and DEFINITELY ensuring that the EZL has a new, thin coating of good quality heatsink paste to couple it thermally to the bulkhead.

R