Speedometer doesn't work but cruise control does.

SOURCE: 97 318i Instrument Cluster

these dashboards are a a pain! there are fuses in the fusebo under the bonnet, check them firt, also remove them and put them back to see if it resets it, if not then there is a test you can do,,,,,

press the mileage button on the dash, turn the ignition key to position one release the button and the das should perform a complete check, i.e gauges and mileage pixel.

Good luck Davelee, p.s, please rate me.

SOURCE: How would I know the ABS is working correctly on my BMW 2001(e39)

find a safe area where there is some sand on the road ot wet leaves or something that will make traction a little less than ideal. drive into it and hit the brake pedel as fast and hard as you can. if the abs works it will activate. it feels different on different systems and i am not sure what bmw does but some will groan very loud, some the brake pedel will push up against your foot some cause the car to pulsate. basically you should feel something unusual in the brakes and it should not do a long hard skid like the cars of the past. you will hear some squeeling but the car will want to resist a constant skid.

SOURCE: my 318 speedometer quit working replaced 2 speed

bad sensors are less common than a faulty ECU.
the OBDII readers they use to trace problems in the car are read through the ecu, not testing the sensor itself, but the reading of it from the euc.

my bmw experiences leads me to the wet eci box.

the ecu compartment is under the windshield on the passenger side on E36

you gain acess to it under the hood....
this compartment gets wet, the ecu lays on a flat surface in that
compartment.

the bottom side of the circuit board gets wet and starts corrosion.

remove the ecu, take the bottom plate off, clean the bottom of the circuit
board with alcohol and a soft tooth brush.

you should be able to see the signs of corrosion or conductive build up.

this gunk bridges solder points doing all sort s of wierd things to your
car, including false sensor readings from asc/abs controllers and other
sensors....

all the way to engine failure and worst case burnt and shorted wiring
harness.

I'm on my 3rd ecu, took me and the repair boys a few years to figure this
one out.

BTW: i would get that ecu mounted above that flat surface, use some sort
of standoff to raise it so that it is not laying in the wet.

SOURCE: my 92 7 series cruise

Most common problem is a failing brake light switch. The cruise control disengages when you touch the brake, and it is designed to fail to the "cruise off" mode (for obvious reasons).
The switch should be on the forward side of your brake pedal arm. They are usually a bear to get to unless you have a helper with very small hands. You may have to crush the old one to bits with a pliers to get it out, That is the normal procedure.
If you have one of those rare '92s that came with a manual transmission, you have a similar switch on the clutch pedal arm. That may be the one that has failed.
There are, of course, many other parts that can fail, but if the mechanical parts under the hood look OK, and everything is plugged in properly, the brake light switch is the first suspect.

SOURCE: have a 2000 740il bmw, speedometer not working, abs light is on. replaced the left side front and rear wheel sensors, but still no speedometer

sounds like a broken cable i would recomend taking it to a dealer and having them check and replace it if thats truly the problem they can get it in and out faster