Removing the RPM Sensor on an 85 Wagon

I have search the forum and I have found lots of reference to the RPM Sensor, which I have tested and found to be bad on my 1985 300TD Wagon. I have looked the Sensor on the driver side on the transmission and I removed the plug that goes to the EGR Control Unit and tested the sensor directly.

My question is how do I remove it? There is a white trim piece that locks the plug in place but I could not see how to remove the sensor itself? Is this a difficult job? How do I remove it? If I remove it will it dump transmission fluid?

Thanks For your Help...JAson

[Pete Burton]

not familiar with the 85 but it stands to reason that RPM sensor is not mounted on the side of the transmission. The engine is connected to the trans via a fluid drive (torque converter), so the engine can be turning while the trans is not

I probably have my nomenclature confused here. I'm talking about the sensor for the EGR Control unit that measures engine rotation speed. This sensor, I thought was on the crank case driver side, and measures rpms to the EGR Control Unit which then reports this information to the Tach.

At anyrate, my tach does not work, and it is because it is not recieving the signal from the EGR Control Unit, which in turn is not geting the signal from the RPM Sensor, which I tested according to the Tech Manaual section 14-100 and 14-50. The manual also points out the localtion on the sensor, but the picture are fairly poor quality.

The 85 and california cars are different than earlier models. This is not the Tach amp issue, the EGR Controler Unit ampifies the signal. But my case it's not getting one to ampliy, so I'm trying to find the sensor, and repair of replace it.

Any help you can give would be helpful, and appreciated...

Jason