Pinout Box (for troubleshooting ABS System)

[rjfranken]

One variable on sensors; I have seen this on cars where the brake pads were metal to metal for a while. The sensors need to be free from metal dust. Being a magnet, metal particles are attracted to it and masks the strength of the signals oscilation. Compressed air is the way to clean them.

[padgett]

Fronts are fronts and rears are rears but are the same for 88-90 and the only difference between fronts and rears is the orientation of the screw hole.

[Guest Kitskaboodle]

Good, I'm glad i dont have to find ones off a 90 then.

I'll try to swap out the fronts this weekend and report back.

Thanks, Kit

[Guest mongeonman]

take a good look at the toothed rings if they are not loose on the shaft,this would give an rratic signal to the sensor cause it would stop turning or not turn the same speed as the other ones,i have had this happened once.

[Guest Kitskaboodle]

Good news!

I swapped out my relatively new front sensors for some used ones that

I pulled off an 89 at a local Pick-N-Pull. The ABS light has now gone out!

After installing the 89 front wheel sensors I took it for a test drive and at the "magic number" (12-13 mph) the ABS light did not go on! (for the 1st time in 4 years!)

Ronnie.....you were saying earlier to do a voltage test of the replaced sensors and not to rely on the ABS light going out. Why?

Just for comparison sake AND because someone on this board mentioned that I might have got the wrong front wheel sensors in the first place, here are the actual p/n's taken right off the top of the sensor housings. Keep in mind there are 3 sets of numbers on these sensors.

89 front sensors : (both left & right sensors have the same exact info)

#3358

10.0711-1144.1

1648453

90 front sensor: (left / driver's side)

#1062

10.0711-1173.1

3521271

90 front sensor: (right / passenger side)

#1062

10.0711-1178.1

3521271

By the way, I matched up the 89 sensor bodies with the 90's and they appear to be identical in length. I did this in order to confirm that it wasnt a sensor to toothed ring gap issue.

I want to take this opportunity to thank everyone who gave their input and advice on this seemingly impossible problem. There were times during this that I wanted to quit and throw in the towel but everyone's encouragement (and ya'all keeping this thread alive) kept me going. THANK YOU!!

P.S. I am now going to start to a new fresh thread on my next problem, the dreaded "Electrical Problem" light.

[Ronnie]

Good news!

Ronnie.....you were saying earlier to do a voltage test of the replaced sensors and not to rely on the ABS light going out. Why?

Just for comparison sake AND because someone on this board mentioned that I might have got the wrong front wheel sensors in the first place,

What I was trying to say was that you should verify the sensor being bad by checking the voltage output because other things can cause the light to stay on besides the sensors.

It was me who suggested the front sensors could be wrong. It appears the part numbers for the '90 model were the correct part numbers.

One of the new sensors must have been defective. I wish you had done the voltage test on each one of them after installing just one of the '89 sensors to determine if the problem was one bad new sensor or both.

I'm happy to hear you got it fixed and that I might have been able to offer some help.

Edited November 7, 2010 by Ronnie (see edit history)

[wws944]

The thing I still don't understand is how *both* 'new' sensors were bad. Kit told me that they were both AC Delcos, sold to him from a GM dealership. I'd think the odds of this happening are pretty high. Nonetheless, it was great to hear that the '89s sensors worked! (I still say there was no reason for that '89 to be in the yard. The interior was a bit worn, but the rest of the car was in good visual shape. Too late now.)