mikew968

While at Mid Ohio this weekend I lost ABS on Friday and then the speedometer on Saturday. I have done a pretty thorough inspection and find nothing wrong. Is this the ABS sensor on the left wheel? Does the ABS and speed sensor work off the same sensor?

Thanks, Mike

RajDatta

Yes and yes. I would check the sensor and the connectors for continuity.
Raj

mikew968

Raj:

Can you give me additional instructions on checking the sensor or the connections?

Thanks, Mike

RajDatta

My money would be on the ground cable from the sensor connector. They get brittle over time and snap off. The ground is on the strut. check that 1st to see if its broken. Its a 10mm nut.
Raj

mikew968

All connections look good but I did not actually take apart and clean although the left wire connectors are clean. Any other thoughts? Should I buy a sensor and swap out?

Thanks, Mike

RajDatta

Mike, that is the expensive way to troubleshoot. Have you checked the obvious? relays and fuses?
Raj

mikew968

Raj:

I have checked fuses. How do you check the relay (s)?

Thanks,

MIke

RajDatta

Mike something like this is up Dave Greimann's alley. Have you considered dropping him a line at 968engineering.com
Raj

mikew968

The problem ending up being a ground behind the instrument panel from when the the door was replaced. re-attached and all is fine.


Mike

RajDatta

Wow, that must have taken some work to figure out. How long did it take you to nail it down?
Raj

Dave in Chicago

Per previous thread (I think), my similar problem turned out to be a very loose ground under dash near original location of ABS brain box (now relocated for cage install).

I've gone weeks now and pounded it at the track and no intermittent ABS light. NICE!

Now, I just have to regain my confidence that the bloody thing is always ready when I push the center pedal down hard

mikew968

Raj:

I double checked the socket for the relay and found it had no ground. This was after I had checked it a bunch of times before as well as a lot of other things. When I was getting the car aligned and corner balanced by John Wright he looked at the wiring diagram and in 5 minutes located the loose ground. Look for the simple things first. I ran the MO race this last weekend and used the s**t out of the abs and it worked great. The good news is I learned a lot about the ABS system and how relays work!


Mike

mikew968

My ABS is out again!!!!!!!!!! This time it comes on after driving for 1/4 mile and stays on. I have a new wheels sensor and will try swaping it out one by and see if I find the problem. I am also going to wire in a ABS relay as well. I will check ground wires for sure!! The funny thing is the ABS starting acting up on Sat practice/qual and was fine for the race. On Sun the ABS light was on all day!


Mike

long_beach_968

I once had my abs go out, the light would come on after driving about 100 yards, so I knew it had to do with the sensors. I cycled changing them out one by one with a new one until I found the culprate

mikew968

I have a new sensor for the front and did the drill with no luck. I removed the rear sensors and checked everything and found 1 side to have some damage. I had a wheel nut back off last year and allowed displacement in the rear axle and bearing and the abs ring contacted the sensor but I am wondering why it would take a year for the damage to appear. I will get a new rear sensor (different from the front) and try changing out. I am becoming more knowledgable about abs than I care to be !!!!!!!!!!!!!


Mike