abs diagnosis
08-01-2006, 08:36 PM
#1
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abs diagnosis hey guys,..
I am sure you will tell me to get it scanned but here is what I've got. 1993 Trans Am with abs inop light on. The self check is fine and the light goes out. Check at 8mph and the light comes on. I cleaned all pigtails at all three abs wheel speed sensors, harness and such. Checked resistance from all three abs wheel speed sensor pigtails to the computer harness and I have a waveform to the harness. If I pick the rear end up and put the car in drive the abs will kick. If I pick up the left front and spin the tire, the abs will kick,..pick up the right front and spin the tire,...nothing.
I disassembled the hub assemblies and swaped hubs and no change. 
Again,..I am receiving signal to the pigtail at the abs computer, but no response from the computer to engage the system due to a variance from the right front speed sensor. I got pissed off and pulled the gauges and pulled the light out that illuminates the abs inop light. 
Deep Breath....I think the actual EBCM is gone.....
What do you guys think?
I am sure you will tell me to get it scanned but here is what I've got. 1993 Trans Am with abs inop light on. The self check is fine and the light goes out. Check at 8mph and the light comes on. I cleaned all pigtails at all three abs wheel speed sensors, harness and such. Checked resistance from all three abs wheel speed sensor pigtails to the computer harness and I have a waveform to the harness. If I pick the rear end up and put the car in drive the abs will kick. If I pick up the left front and spin the tire, the abs will kick,..pick up the right front and spin the tire,...nothing.
I disassembled the hub assemblies and swaped hubs and no change. Again,..I am receiving signal to the pigtail at the abs computer, but no response from the computer to engage the system due to a variance from the right front speed sensor. I got pissed off and pulled the gauges and pulled the light out that illuminates the abs inop light. Deep Breath....I think the actual EBCM is gone.....
What do you guys think?
08-01-2006, 08:49 PM
#2
It's nice to see that you went through a few troublshooting tests. The circuit can be difficult to check when you cant verify specific critera.
You're not missing anything by not having ABS. Remove it and don't look back. FWIW, your year car is rather simple to shut off the ABS lamp without going into the dash. The EBCM, if it is damaged, you'd probably not have any control of the other channels. It may be one of the modulator motors which have gone bad...it's really guessing at this point.
...If you're interested, we do have a ABS delete kit that will enable you to completely remove the entire modulator and bracket to clean up the engine bay. It will also drop ~16 lbs from your engine bay and help air circulation slightly. The kit also contains a proportioning valve and optional line lock (if you don't have one yet).
You're not missing anything by not having ABS. Remove it and don't look back. FWIW, your year car is rather simple to shut off the ABS lamp without going into the dash. The EBCM, if it is damaged, you'd probably not have any control of the other channels. It may be one of the modulator motors which have gone bad...it's really guessing at this point.
...If you're interested, we do have a ABS delete kit that will enable you to completely remove the entire modulator and bracket to clean up the engine bay. It will also drop ~16 lbs from your engine bay and help air circulation slightly. The kit also contains a proportioning valve and optional line lock (if you don't have one yet).
