Need Wiring Help / Identify

[Ryan1984]

I posted this on LS1tech, but didn't get an answer so figured I'd try here

So...I saved my new (to me) '99 Z28 from a possible fire last night. I noticed the lights kept dimming, and I could hear a sparking sound. So, I pulled the radio out and there's a black box located behind the radio / hvac controls. It's a aprox. 4" x 4" square with two sets of wires going into it. It actually slides into grooves on the dash support to stay put.

Anyway, the big power wiring going to this was rubbing on a metal part of the dash structure and was shorting out on that. The wire is in pretty bad shape from that. I taped the wire up as a temp fix to hold me over until the weekend when I can really get in there and replace the wire.

So, I start the car back up and the idle is off. RPM's drop almost to the point of stalling, then surge back up. It just keeps repeating that process. SES light is on, but I don't have a scanner to see what it says.

What I'm wondering is what that black box is. I'm thinking the short probably fried / damaged whatever it is. So, If the box does something that would affect the idle, that would let me know I need to replace it. I find it hard to believe that it's just coincidental.

[pajeff02]

Just for giggles, check your fuses -- look for "ENG SENS" and make sure that it is intact.

[JayTA98]

I posted this on LS1tech, but didn't get an answer so figured I'd try here

So...I saved my new (to me) '99 Z28 from a possible fire last night. I noticed the lights kept dimming, and I could hear a sparking sound. So, I pulled the radio out and there's a black box located behind the radio / hvac controls. It's a aprox. 4" x 4" square with two sets of wires going into it. It actually slides into grooves on the dash support to stay put.

Anyway, the big power wiring going to this was rubbing on a metal part of the dash structure and was shorting out on that. The wire is in pretty bad shape from that. I taped the wire up as a temp fix to hold me over until the weekend when I can really get in there and replace the wire.

So, I start the car back up and the idle is off. RPM's drop almost to the point of stalling, then surge back up. It just keeps repeating that process. SES light is on, but I don't have a scanner to see what it says.

What I'm wondering is what that black box is. I'm thinking the short probably fried / damaged whatever it is. So, If the box does something that would affect the idle, that would let me know I need to replace it. I find it hard to believe that it's just coincidental.

Is this box kinda to the right of the radio area on the back? does it has an black/orange plug and black/blue plug? If it does, that box controls the DRL's and some other things. I know it also controls the brake light in the cluster and it controls the trunk release in some models. To my knowledge it doesn't control anything related with idle but i'm not 100%. i'm sure someone will chime with more info about that.

If you can get it scanned and see what codes are coming up you can then pin point if a sensor and/or it's wiring got fried. I will start by checking all your fuses like Pajeff suggested before anything else.

[35th-ANV-SS]

The only thing that comes to mind that is a black box that size is the Brake Control Module (BCM) and from what I remember, it is under the dash usually, towards the passenger side. It may be year dependent though.

[JayTA98]

The only thing that comes to mind that is a black box that size is the Brake Control Module (BCM) and from what I remember, it is under the dash usually, towards the passenger side. It may be year dependent though.

yes you are correct about the BCM (Brake Control Module? i thought it was Body Control Module... but i have been incorrect before) location. But he says that the box is behind the radio once he pulled the radio out. That sounds to me like the small box that controls the DRL's

[35th-ANV-SS]

Yes, I had EBCM on the mind

[JayTA98]

is it this box? this is the box that controls the DRL's

http://xse.com/leres/ss/images/drl4-sm.html

[JayTA98]

Yes, I had EBCM on the mind

the Emergency Brake Control Module? lol?

[35th-ANV-SS]

I believe that is the BCM. It sure looks like it from what I remember at least. His box is probably what you mentioned.

OP - get your codes read at Autozone or Pepboys for free and report back!

[35th-ANV-SS]

the Emergency Brake Control Module? lol?

Close Electronic Brake Control Module.

[JayTA98]

this is the BCM that is underneath the passenger side
http://i20.ebayimg.com/02/i/001/23/7...t_id=800005007

[JayTA98]

Close Electronic Brake Control Module.

So there is a BCM and an EBCM? im confused?

[35th-ANV-SS]

So there is a BCM and an EBCM? im confused?

Pretty sure that is correct. I could be wrong though.

[Rons 98]

Exactly how do you remove the bcm; and where exactly is it. (1998 trans am)

Thank You Much