Speedo Sensor Issue

[Dre220136]

Hi all,

Im having an issue with my speedometer needle dropping randomly, also affects tachometer

Ive replaced the differential speed sensor, at first it seemed like it was fixed but now it started happening again, although not as often as before,

ive cleaned the sensor again and the harness with some carb clean, issue persists, any suggestions?

Thanks

[MarcoZandrini]

First of all, it's a good idea to provide info about the car. This include model, year, mileage, transmission type and driveline.

Your car's speedo isn't run from a differential sensor. It uses the 4 abs wheel speed sensors to determine speed.

Because the tach is acting up the problem isn't the speed sensors but something electronic.

[BimmerBreaker]

Wheel speed sensors?

[Dre220136]

I have 98 328i 5spd, after reading some posts on the forum about guys having similar issues they typically replaced the differential sensor so given that the part was

only 30 bucks i went for it. my ABS hasnt worked a day since i bought the car two years ago

[Pelican Parts]

I would try pulling the codes since you have a 98' with an OBD2, it'll at least give you an idea of any stored codes that relate to the issue that you're having.

[MIKYZZ4]

A scan with a BMW specific scan tool/software would be ideal,
but you can perform a quick check of the wheel speed sensors & crank position sensor,
for clean, snug connections.

[MauiM3Mania]

Moved from General BMW sub-forum.

[JDStrickland]

If the speedo and the tach are doing the same thing, the speed sensor is not the issue. I don't have my schematics close by, but my money is on a ground for the instrument cluster is on the fritz. Something common to the gauges on the cluster, not the inputs to those gauges. The tach comes from the engine, the speedo comes out of the differential. For both to fail together, you need to have an issue with the computer or the ground to the cluster.

- - - Updated - - -

First of all, it's a good idea to provide info about the car. This include model, year, mileage, transmission type and driveline.

Your car's speedo isn't run from a differential sensor. It uses the 4 abs wheel speed sensors to determine speed.

Because the tach is acting up the problem isn't the speed sensors but something electronic.

The E36 has 5 speed sensors, one on each wheel and one on the differential. The wheel speed sensors monitor tire rotation, or the lack of it, and engage the traction control or ABS, as is appropriate. Vehicle speed comes out of the differential.

[Dre220136]

Thanks for all of your replies, the code i was getting is 0500, but it might just be the Dash cluster like JDStrickland mentioned,

Anyone know if i can put an m3 cluster in the 328i?

[MIKYZZ4]

The code is indicating it's the speed sensor circuit, so why are you focusing on the dash cluster?

[Dre220136]

The code is indicating it's the speed sensor circuit, so why are you focusing on the dash cluster?

As i mentioned in the original post, i have bought a new speed sensor already and also cleaned the connector and the sensor with carb clean, which

led me to believe the problem isnt with the sensor itself

[MIKYZZ4]

There is more than 1 wheel speed sensor!