Please help: Speedometer Impulse Sensor?

[asheridan07]

What would be effected if the Speedometer Impulse Sensor were to go out?

I have a 1990 325is, and the Speedo, Odometer, and Fuel Economy gauges are not working on my cluster. I don't really think it's an SI board issue due to the fact that my Tachometer is still working and the OBC is not reading an Avg MPH or an Avg MPG either. The cluster and OBC are separated, right? Makes me think it's a sender problem? Thus my question about the speedometer impulse sensor. Any help guys? Thanks!

_Alex

[EN318isPDX]

What would be effected if the Speedometer Impulse Sensor were to go out?

I have a 1990 325is, and the Speedo, Odometer, and Fuel Economy gauges are not working on my cluster. I don't really think it's an SI board issue due to the fact that my Tachometer is still working and the OBC is not reading an Avg MPH or an Avg MPG either. The cluster and OBC are separated, right? Makes me think it's a sender problem? Thus my question about the speedometer impulse sensor. Any help guys? Thanks!

_Alex

Check the wires going into your diff?

[asheridan07]

Check them how? The plastic covering was pretty caroded.

[BMWManiac]

Yes, all those would be affected. Remove the sensor from the diff and make sure its not covered in crud....clean it, reinstall it.

When the speedometer doesn't move, your mileage won't change, and your fuel economy won't budge....basically, just like idling....