I have a 1996 Z28 with a 6 speed.

Recently put eBay headers on my car. When I put the headers on we took the air pump and EGR off the car.

I had MadTuner tune my PCM.


When I start my car the security system goes on and off, abs light is on, and the traction control light is on. The security system goes off after a few min, as soon as I get in the car it starts going on and off again. We didnt touch the abs brakes and only moved the traction pump out of the way.

I had my battery tested and it tested out fine. Didnt trust it so I had a friend drive his camaro up today and tried his battery, car does the same thing.

When I am in the car I can hear a relay deep in the dash making noise.



I have a 50 htz module and ignition relay grounded out to get past my vats system.


Please give me some ideas on what to try, what to do, etc.


I think I can get rid of the 50 htz box and un ground the ignition relay now that I have Vats tuned out of the PCM.

All fuses look good, all turn signal, brake, etc are brand new and work.
Other than this, I dont know what to even try.

 

The ABS and ASR are both run by the same "pump". What parts did you move?

All it takes is a loose wire, and both the ABS and ASR system will shut down. I'm assuming the "lights" you are referring to are the "ABS INOP" and "ASR OFF" lights?

 

We undid the two bolts that hold down the pump under the black cover and moved it to where the the pilers are, zip tied it to my wipers to keep it out of the way.



So how do non traction control cars ABS function?

 

The unit on top of the valve cover is an electronic throttle cable actuator. That is used to control the throttle during TCS actuation, while the PCM plays with the timing, and the ABS pump tweaks the brakes, all based on input from the EBTCM module.

The difference between the ABS unit in the ABS-only cars and the one in the ABS + TCS cars is in the number of motors used. ABS-only uses a single motor to control hydraulic pressure in the single line that serves both rear brakes, ABS+TCS uses two motors and two lines to control each rear brake independantly. Visually, they look like the same unit.

If you have knocked a wire loose from the throttle positioner, its going to shut down the TCS. Not sure what affect that would have on the TCS.

 

I think it could be the BCM.

Does the BCM handle the security system, abs, or traction at all?

Also, I had vats issues, and my power door lock will only lock the doors, not unlock the doors.



If I were to purchase a new BCM, how do I tell which of the 15 resistance pellets I will need for my key? Looking at my BCM it doesnt say anything on it.

Thanks for the help!!!

 

Shoebox has the wiring diagram for the 96 BCM:

http://shbox.com/1/bcm_1996.jpg

A quick look shows it interfaces with the security and PASS-KEY system. I didn't see any input for ABS or ASR. Those are in the EBTCM. You might want to look the BCM diagram over more carefully, to see if it contains any clues.

 

Is there a I can get what code the BCM has in it?

Can the dealer "interrogate" the BCM to do this?

 

Just purchased a 96 BCM out of a Camaro on eBay.

Ill have to get some resistors next.

 

Shoebox has a guide to pulling the BCM codes:

http://shbox.com/1/4th_gen_tech2.html#bcm

 

Swapped in a different BCM I got from a friend. Security issue went away. Car seems to function as normal besides the windows do not work. The car that the BCM was originally in was a crank window car.

Are power windows a function of the BCM?

 

The power windows are powered via the retained accessory power (RAP) feature, which is part of the 96 and later BCM. The radio is also on this cirucuit.

From Shoebox:

http://shbox.com/1/bcm_1996.jpg