1995 LeSabre ABS

Anyone know the part number for the front ABS sensors? I've lost the ABS and been driving without it. Now my 16 year old is driving it and it might be a good idea to have them work. Caught our first snow in CT yesterday. I have in the past blocked it us and read the resistance through each sensor at the wheel and they read the same at the same speeds. Although it was had spinning the back wheels by hand but those look approximately the same. I replaced the computer with one from a wreck and no change. Light is always on. There's some GM sensors on EBAY but I have no idea of part number for my car. Any and all suggestions on PN or trouble shooting appreciated. Dealer wants $100+ to troubleshot and claims he must fix a defective brake system if it comes in.....

As the ABS Sensors exist to monitor the functioning of your brakes, I doubt spinning your wheels would change the resistance output.

The ABS system engages when the brakes are being applied and the wheel stops turning sooner than it should as calculated using data from the transmission speed sensor and in comparison to the behavior of the other wheels.

So the ABS Sensors likely only produce a varying reading when the brakes are being applied. The resistance would then change depending on how much wheel movement there was up to a certain point. In addition to monitoring wheel movement, I expect there is a sensor that monitors the status of each brake solinoid.

The ABS control module performs a large amount of checks on the ABS system at start up. The sensors are only one thing that it would check. There's a brake fluid level sensor, that would likely cause a ABS light. At start up, the ABS system cycles all the solinoids in the accumulator to confirm they are working correctly, and the correct pressures exist.

There's a large round connector behind the drivers headlight on my 1995 that connects all these wires back the ABS module. If this is damaged, loose, or corroded, it would cause a light. There's probably even a vacuum sensor that monitors the vaccum being applied to the master cylindar.

The problem with working on ABS yourself is that the troublecodes largely aren't reported to do-it-yourself scan tools. Most economical scan tools only read Generic GM codes of Generic OBD-II codes, which are codes that effect the general powertrain and emissions... i.e. The Service Engine Soon light.

ABS, Air Bags, Power Seats, Radios, all fall into the catagory of "enhanced codes" and are manufacturer specific. The Tech2 GM scan tool, and most of the $10k tools, read these codes and are able to perform ABS tests by request, like cycling the solinoids.

There's reasons things like Air Bag and ABS don't report their codes under the generic system. The most important of which is that they are safety systems. If you mess with it, install the wrong part, screw up the system, and as a result loose your brakes at 65 MPH... that would be bad and someone would end up liable for you messing with your car.

In addition to that, it's pretty well impossible to get trouble codes from a 1995 LeSabre. I know, I have one. They aren't OBD-I or OBD-II, they have features of both, and thereby lack the features needed to make it easy. I'm currently in the process of ordering circut boards and microporcessors to build an my 3rd version of an interface for my laptop.

Beyond that... and to finially end my babbling. Yes, if you take your car to a mechanic for something like an ABS repair, they are legally obligated to correct the problem before releasing the car back into your custody. I'm sure they will make sign a form agreeing to such. This is because ABS is a safety system, if they let you leave with the car unrepaired and you have a wreck, they are then liable for not repairing the system.

Thanks for the reply. Yes, unfortunately I know all about the trouble code situation on my Buick. I have the connector from one configuration and the "computer" from another. Bummer.

I figured that the resistance chek might work as the the "fins" on the ABS rotor and the sensor seemed to be a reluctor type set up, similar to a cam or crank sensor. Figured if on sensor was bad, it might show as an "open" or if the sensors didn't match, I'd have something to work from. I pulled all the connectors and reconnected in case of corrosion. No luck.

So, I'll try to come up with some other ideas. Again, appreciate the comments. As the brakes work without the ABS, (at least some designer understood the concept of failsafe). I'll keep thinking on it.

Also, this beast just has ABS, not ABS with traction control. I hear that this makes it harder to find used parts. Be well and thanks.