All,

I really need help. Out of the blue my ABS INOP light came on and i'm not really sure where to start my troubleshooting at. Can anyone give me a few things to check? And please be specific on where to look and what to look for please. Not real familiar with the ABS system. But, after the car is started the light stays on. My poor 94 Z28 is in need and i can't help it right now. Help me Obi Wan, you're my only hope!!!!!

Garry

 

Look at the sensors on the inside of the rotor dirt gets in them and they cant read the magnet it passes by.
Not sure where yours are located due to well not having owned a chevy vehicle newer then 87.
But have owned my same z since new.

 

Your 94 F-Body has three ABS sensors..... one in each front wheel hub assembly, and one on top of the center differential housing. The most common problem is with the ones for the front wheels. Dirt, as mentioned above, or corroded or loose harness connectors. The back can also be a problem if the sensor gets covered in metal particles. In the front, unplug the harness connectors, clean both ends and reconnect. In the back, check the harness connector, and pull the sensor out of the differential housing and clean it off.

It may also be a problem with the center mounted stop light.

 

Glad to see I wasnt to far off on the prob. Thanx.

 

These other guys are right. Most often it is a wheel sensor or a water jacket(plug connection on the ends of the harnesses) either at the wheel or where they connect to the main harness. Make sure you look at the end closest to the exhaust headers, they may have dried out and lost good connection. On my '98, there are two in the front, as mentioned by the others, and one in the back. You can unplug the harnesses one at a time and inspect them for wear or a dirty connection. If the wire insulation happens to be worn through(happened on mine) it can ground out against the chassis. You can repair this with electrical tape. Also, make sure the harnesses have good wire loom protecting them. This helps.
Your car has two primary control modules, one for the engine and tranny and one for the abs system. It is designed to de-activate the abs if there is a problem. Start with the wires. If you can't find anything obvious, take it to a shop and pay a few bucks to get a computer diagnostic. Unfortunately, aftermarket repair shops don't usually carry GM's programmers and software. You typically need GM's computer to tell your main PCM to extract info from the ABS system. Most code readers can't get the ABS info. Do you have traction control? If so, that module could be warn out also. It happened to mine. They're expensive, so look into used ones if that is what is wrong. Make sure you find out exactly what is failing and don't just start replacing expensive parts. It could be many things. Good luck.

 

I almost forgot, if it is just the harness and you are able to repair it, the warning light should turn off when you start the car up. If you still get the light after trying this, you should seek help at the shop.

 

Traction control was not available on the 94's.