I just recently had 3.73 Strange gears installed in my rear axle (2.73 originally, so Series 2 carrier). Now after I have everything put back together I am getting an ABS INOP light. I also replaced the ABS sensor on top of the rear axle because I had broken the plastic wire clip portion of the sensor. I reprogrammed my PCM using C.A.T.S. RT Tuner for the correct gear ratio and tire size. I adjusted the shift tables as well (A4). I hooked my car up to Datamaster and made several runs with it and the ABS INOP light comes on after I pass about 15 MPH in drive, but I don't pick up any engine or transmission DTC's with Datamaster. Is there another program I should be using or some other place I should be looking in Datamaster for what this problem might be?

I tried downloading Freescan off the website but I am unable to log into the FTP site...

The only other thing that I have thought about trying is putting the old rear axle ABS sensor back in to see if it works, which I will probably try tomorrow. Any other ideas for me?

Thanks.

 

No software available for these cables will scan ABS codes. A dealer Tech 1 or Tech 2 tool will, however. If you upgraded the carrier and didn't change the reluctor wheel, this is your problem.

 

So I am guessing that a cheap OBD-I scanner (like an Actron) won't pick up the ABS codes either... Is that correct?

No, I stuck with the Series 2 carrier. I just put in the Series 2 3.73 Strange gears.

 

Check your third brake light bulbs, or do you have an aftermarket spoiler with led's? Either of these will set an abs light and make cruise inop.
Just a simple check for you.

 

Well, I swapped in the old sensor and still have the ABS light coming on. I took my car to someone that I know who has a Tech 1 scanner and they pulled two codes from the ABS history. One of those codes was rear wheel speed sensor excessive speed detected and the other one was a rear wheel sensor short. Does anyone know what the bounds are for that sensor? Can it even produce a shorted condition or does that definitely mean I have a short in the wiring going back to the sensor? I am going to try some continuity tests with the wiring going back to that sensor and see what I get.

I also just painted my rear axle when I put new gears in it. Does anyone know if that sensor grounds through the mounting bolt and through the axle to the frame? I wouldn't think that it does, since the axle is pretty much isolated from the frame.

Any help is appreciated. Thanks.

 

Those "scanners" only scan the PCM. To check the ABS and TCS systems, you need to access the EBCM computer.

 

is one of your 3rd brake light bulbs out? my buddies abs light in his 94z would turn on whenever one of those bulbs burnt out. Its not to technical and may be only specific to his car but it wouldnt hurt to check!

EDIT: whoops, didnt read everyones posts just seen a327vette's post, well thats a second vote for checking 3rd brake light bulbs!

 

How are you using C.A.T.S. RT Tuner with a '94? I thought this only worked with the chipped cars. I may be mistaken though.

 

Yep a third for the checking the third brake light but if there were any teeth missing on the reluctor wheel it would do the same thing and set off the inop light.

Mikey

 

Is there a reluctor on the Strange setup to allow for ABS operation?

 

The reluctor sets on the differential carrier, correct? All the Strange set up that I have includes is the ring and pinion gear. I am not totally sure how the set up goes since I had someone else put the gears in for me. Looking at the parts breakdown it looks like the reluctor might go over the lip on the differential carrier... I would hope that if the reluctor goes on the ring gear that the Strange setup has whatever is needed for the reluctor. Does anyone who used a Strange Series II ring and pinion gear set still have their reluctor ring on it and their ABS is working properly?

Unfortunately I have been busy at work and working on another family car (water pump and timing belt) so I haven't had time to trace this problem down. I will keep you all informed.

Thanks again.

 

Well, I did some more testing this weekend. I traced the wiring from the connector to the rear wheel speed sensor up to the EBCM and checked continuity on both wires, that was fine. I also checked to make sure they weren't shorting on themselves as well, and they weren't. I forgot to check each for continuity to ground, but I would hope that isn't the case. I also hooked up my AC voltmeter to the sensor to see what kind of output I was getting while running the car on jackstands. It seemed like I was getting somewhat valid numbers, but they were fluctuating quite a bit, even at constant speeds. I am guessing that's where the excessive rear wheel speed variation code is coming from. So to me, this is still pointing to the reluctor wheel in the axle (since I have two sensors and both do the same thing).

Does any one know what the tolerance limits are on this sensor as far as high value and maybe even allowable tolerance values before it throws an excessive speed variation code?

Thanks.