OK, I have finally put it into my mind that I am going to fix the brakes in my car. I have a 93 Z28 that I've had for a while now. I have several common things that cause BRAKE/ABS INOP light to come on. I have read that in the 93, being PROM chip based that there are additional problems. Sometimes when I start my car, both lights are on.. sometimes it takes a few seconds for them to illuminate. Recently I have almost gotten into a few accidents because my front tires lock up, i.e. no ABS at all. I have the following problems:

I have an SS spoiler in the back and have no installed the automotive relay fix.

I have a non-stock gear ratio (3.73) installed in the car.

If I go through and do the automotive relay in parallel with the brake light fix, will this solve the issue? I have been under the impression that this simply takes care of the light. I haven't found any posts in this forum that actually state the owner lost ABS BRAKES, just that they had the light come on.

Thanks for the help.

 

I'm sorry, I posted this in the wrong forum. I saw chassis/suspension and brake and got excited. Could an admin please move this to the correct spot?

Again, sorry I wasn't paying attention. Thanks!

 

Moved!

 

The ABS system has nothing to do with your ECM or the chip. ABS is controlled by the Electronic Braking Control Module (EBCM). You can have the codes read off the EBCM with a Tech-1/Tech-2 or other high end brake scanner.

When the "ABS INOP" light is on, you will not have ABS. But you should easilly be able to control stopping your car, without locking up the brakes.

The "BRAKE" light needs to be fixed first. That can indicate unbalance braking pressure in the front and rear brake systems. If you don't have enough braking in the front, or in the back, the part of the system that is working is the one that is most likely to lock up - you are doing 100% of the braking with either the front or rear brakes.

After you fix the "BRAKE" light, and correct the SS spoiler third brake light problem, the ABS INOP light may go out. If it doesn't you either have to have the EBCM scanned, or start checking the wheel sensors, and rear axle sensor for dirt or loose connections.

 

JasonD: Thanks for moving the thread

Injuneer: Thanks for the info. I think I may have found a source of at least some of the problem last night. The giant bundle of wires that runs next to the steering column, well mine has been running too close for quite some time and the steering column has worn through the cable organizer as well as the jacketing on some of the wires. Once i get some daylight i'm going to go in and re-insulate the wires and then try and figure out some way to stop the wire chaffing.

A couple of questions i haven't been able to find on this message board. The schematic makes it look like the relay is hooked up in such a way that the coil is in parallel with the LED load. I Understand this, but is it necessary to use an automotive relay, or was this just used as a sample load? Could i use a high wattage resistor in its place, as i have access to these. If so, does anyone know what resistance value i should be looking for? I'm assuming less than 100 ohms.

2nd question, where is the best location, physically to install this load? As the spoiler was installed before i got the car, i do not know where the wiring is run.

 

UPDATE: I found that my steering column had been wearing against a wire bundle for apparently a long time and had worn through the jacketing of several wires. I went in and covered them in electrical tape last night and had to replace a wire that was worn all the way through (White/Brown). My "BRAKE" light went out, yay! My ABS INOP light is still on but I assume this is from the spoiler. Does anyone have pictures of their installed relay fix?

Thanks!

 

The relay coil is used because it can dissipate the heat that is caused by circuit operation. Most resistors cannot and can burn up/cause a fire hazard. I think people tend to hid the relay in the hatch with the wiring to the light.

 

Can this be used to fix the TSB#569002A, basically the stock CC module is too sensitive from the brake light or brake pedal switch?

If yes, where does this relay go, where do I buy it? Shoebox I looked at your site and saw the diagram for the relay, but I'm retarded. How do I make that thing?