Speedometer/ABS problem

[seanm]

I already checked the speedo FAQ, but it did not help.

The ABS and check engine lights came on and I lost the speedometer. The brakes where a mess (and I knew it) so I got the brakes all fixed up. Now the brakes are working great, although I still have to get used to the small brake pedal travel

But the check engine light and ABS light where still on and the speedometer still did not work. So I replaced the ABS speed sensor. It made no difference and both sensors measure in the valid range.

The OBD2 code was P500. I disconnected the battery, waited 5 minutes, and put it back on. The ABS light came back on, but the check engine light seems to be staying off.

I checked all the fuses related to ABS and the speedo and they are all good. I checked the ABS resistor, and it reads 10k. I checked the ABS diode and it is good.

I don't know how to check the ABS relay I also cannot find the magical test point to get the ABS error code

I really don't care that the ABS doesn't work. I am suspicious that the bad brake fluid has messed up the ABS valve. I can worry about that latter.

But it sorta bugs me that the speedo doesn't work. To be honest, I don't really miss it, expect when driving in max 30/50 zones with police around

So it seems the sensor works, but something that affects the speedo, and possibly the ABS, is broken

 

[desertrat]

Check the sensor on top of the rear differential. But first check the Speedometer advice by Jim Oaks. It is invaluable. This info tells how to check the diff sensor.

If you need your ABS EEC repaired, google up ModuleMaster. These are great people!