Need some help guys please on ABS fault

[stradman]

Hello everyone,
I really need some collective wisdom from you guys to see if I can sort out a problem with my ACR. I seem to be having all the bad luck with this car somehow and would really like to see if I can find a solution

Anyway, I've had a fault indicator/message on my dash that came up a few weeks ago telling me to service the antilock and electronic braking system. This came up on track, and when this comes up the ABS system effectively does not function.

So I plugged an OBD scanner which has confirmed on a number of occasions that there is a right front ABS electrical supply fault. I assumed it was a bad ABS sensor. Car has 15k miles on it. I had even run live data on my OBD scanner to read out the mph of the sensors which confirmed that the right front sensor readout was erratic thereby I presume it was throwing a code, so I thought the ABS sensor change would do the trick.

I've now changed 2 ABS sensors and still the problem persists.

I erased the codes after the sensor changes a few times, but the fault indicator light and message on dash still comes up straight away again. I unplugged battery as well to see if that helps but didn't seem to help.

I even checked out the voltage of the right front lead to the ABS sensor and that showed a good 11.5-12 volts going to the ABS sensor, and all connections look good and clean. Reluctor ring looks good and so I just don't know what else to do.?? Cheers guys
48805

[Steve-Indy]

Have you checked the plug pins and the actual wiring ?

I helped "emergently" rewire a left rear sensor for a guy teacking the car that day. We had to run a new, twisted pair of wires as stipulated in service info. It worked for the rest of that weekend though I suspect owner pursued a proper fix at a later date.

[stradman]

Have you checked the plug pins and the actual wiring ?

I helped "emergently" rewire a left rear sensor for a guy teacking the car that day. We had to run a new, twisted pair of wires as stipulated in service info. It worked for the rest of that weekend though I suspect owner pursued a proper fix at a later date.

Well I did check the pins and wiring, from what I can see at least and all looks sound, but clearly there is a short somewhere I guess but can't see it anywhere obviously. I just absolutely hate electric faults. They just piss me off so much...:mad:

[Steve-Indy]

Thanks for the response...agree this is frustrating stuff. I was hoping that you would find the problem with varying readings while doing a "wiggle and tug test" on the wires.

[Arizona Vipers]

Man there are so many parts to the ABS system. I had similar issues and it ended up being a loose wire to the actual ABS module which is located under the center console cover.

[stradman]

Man there are so many parts to the ABS system. I had similar issues and it ended up being a loose wire to the actual ABS module which is located under the center console cover.

That's good input Cable. So last week I disconnected the Right front ABS sensor and tested the terminals in the connector on the vehicle(loom side) and I had about 11 volts so I thought it was obviously the sensor. Today I double checked it again, as ABS still wasn't working, and there is now zero voltage going to the sensor from the loom. The actual connector and terminals , and wires going to the connector from the loom, look good and are not loose. So either, there is for some reason, no electricity at the terminals of the connector, because of a bad connection within the connector(unlikely though as it doesn't look damaged and wires going to connector look sound) or there is perhaps as you suggest Cable, a loose wire coming from the ABS module more proximally.

The problem is, can anyone tell me where exactly the ABS module is and best way to access it??? You say center console cover-inside the car presumably??? Best way to get to it??
Thanks guys.

[Bob Woodhouse]

Hmm, good advice, let me see if I can further confuse, ABS module may mean different things but the module on my cars rides in front of the left front wheel in front of the inner fender well. I might start at the sensor, verify the voltage we are supposed to be seeing, if none, keep working you way back until you have it. Then run an alternate wire to get up and running. Replace once verified. No one mentioned the clearance between the sensor and the tone wheel. While this is a fixed distance do check it if you seem to be falling in and out of service. It is a critical distance and track cars have a tendency to get fussy from tire rubber or debris getting around there. Cant find the spec, pull the one out of the opposite wheel to compare.

[darbgnik]

If the ABS module is under the center console cover, I have a thread in the DIY section showing how to remove it, from when I did my DSC suspension install. I needed to pull that cover back to access the radio bezel:

https://driveviper.com/forums/threads/13666-DSC-suspension-DIY

[stradman]

Hmm, good advice, let me see if I can further confuse, ABS module may mean different things but the module on my cars rides in front of the left front wheel in front of the inner fender well. I might start at the sensor, verify the voltage we are supposed to be seeing, if none, keep working you way back until you have it. Then run an alternate wire to get up and running. Replace once verified. No one mentioned the clearance between the sensor and the tone wheel. While this is a fixed distance do check it if you seem to be falling in and out of service. It is a critical distance and track cars have a tendency to get fussy from tire rubber or debris getting around there. Cant find the spec, pull the one out of the opposite wheel to compare.

Thanks Bob. I think we have now established that ABS module is in the left front Wheel well(Thanks to Steve Indy input as well.������). I have now also confirmed that I have zero voltage at the vehicle side in the connector with the sensor(when I had voltage a couple of weeks ago) so presumably something has now come completely loose and need to trace back as you say. I presume that the electrical supply to the sensors at each corner originates from the module although that may not be correct.