Speedometer and Odometer No Longer Working

XK8
1

Hi.
My 2001 XK8 has the ACS/TRAC error light on. I read that this may be the result of a bad ABS controller module problem but that it could also be a result of dirty wheel speed sensors. I removed, cleaned, and reinstalled the front wheel sensors (they were not very dirty), being careful not to get any fluid on the contacts. Easy job.
Now … the speedometer is no longer working, nor is the odometer. It lights up but does not register mileage when I drive. (I also get “Low Brake Fluid” and “Incorrect Part Fitted” warnings). The ABS controller module needs to be replaced (one of the pins is broken off) but the odometer and speedometer were working fine.

Can this be a result of a bad wheel speed sensor, or harness, or both? What the heck did I do wrong!? The rest of the car seems fine… (famous last words).
Thanks for any suggestions.

2

The ABS module NEEDS to work because it is a link in the CAN bus.
The ECM, TCM, ABS and INST PK are all on the bus.

The ABS module is the link from the wheel speed sensors to the INST PK for the speedometer. (faulty ABS = no speed indication)

INCORRECT PART FITTED is likely the ABS module fault.

bob

3

Thanks for your advice. In rehooking the harness to the controller module, I noticed one pin broken and several bent. I can straighten the bent ones with pliers (I hope!) but the broken one is a goner. Not sure if I can recover functionality without that pin, but will try. The ABS light was on since I got the car but everything else worked ok. In removing the harness I seem to have allowed gremlins in…
I can order a replacement (though $$). A better option would be to start with reattaching the harness even with one pin missing…
Does that make sense?

4

Hi Jonathan,

I don’t know where you are located but here in the UK there are companies that can repair the ABS module. I expect there are many more who can do it in the US. May be cheaper than sourcing a replacement.

Eric

5

Hi. I am in the UAE, so repairs are harder to come by and sending mine off and back is not only time consuming but expensive with all the shipping. I will likely order a replacement controller module and possibly ABS pump (since they often come together from salvage cars) and that should do the trick (fingers crossed). I am concerned about the missing contact pin on the controller module but will try to straighten the others and get them hooked up to the harness and see if that resolves some of my other problems. I can live without ABS/TRAC but not without a speedometer and odometer!
Thanks!

6

Well, you might be lucky. Pins 10,11,12 & 23 are not used.

Eric

7

Good to know. I will attempt to straighten them out later today and hope to get the speedo and odometer back. I’ll be replacing the unit eventually (may try to solder fix).
Thanks

8

Success! I used some needle nose pliers, a thin piece of plastic from an old credit card, and a small flat file to coax the pins back into shape. After a few tries it worked, and now the speedometer and odometer are back in action, and no more Incorrect Part Fitted or Low Brake Fluid warnings. Oddly, my previous P1637 and P 1646 codes are gone, replaced by a C1175! Seems to be LH rear speed sensor. I can live with that for now (have a new ABS controller module and speed sensors on the way).
Thanks!