Electrical Problems

[edmavalanche]

Having some electrical problems with my 2002 avalanche. It's 2wd with traction control.

 

Long time ago ABS light came on and the pump motor was running. We pulled the fuse to stop the pump and drove until I could afford to try to fix it.

 

 

 

A few months ago, Airbag light also came on.

 

 

 

Took it to dealer, they said something was wrong in airbag but didn't know which part so they recommended replacing all three parts. ($800) They said same about abs, (replace ebcm, pump, etc. $2,200)

 

 

 

Didn't have $3,000 to drop at dealer so I started with the just the ebcm from modulemaster. ABS light stayed on and then instrument cluster started to go crazy.

 

 

 

Message center scrolls between low fuel, battery light and security.

 

Gas guage intermitantly comes one but off most of the time

 

Traction assist light stuck on in off position

 

Check engine light on

 

 

 

Modulemaster said they sent wrong unit so had them send another one. Same problem.

 

 

 

Brought truck to electrical specialist. They said they couldn't get any communication with the any system so they couldn't read any codes. (they have same scanner as dealer) Said dealer best chance but expensive trial and error.

 

 

 

Don't know where to turn next. Is there any way I can narrow down which module might be bad without spending thousands at dealer?

 

 

 

Thanks.

[bossier62guy]

Having some electrical problems with my 2002 avalanche. It's 2wd with traction control.

 

Long time ago ABS light came on and the pump motor was running. We pulled the fuse to stop the pump and drove until I could afford to try to fix it.

 

 

 

A few months ago, Airbag light also came on.

 

 

 

Took it to dealer, they said something was wrong in airbag but didn't know which part so they recommended replacing all three parts. ($800) They said same about abs, (replace ebcm, pump, etc. $2,200)

 

 

 

Didn't have $3,000 to drop at dealer so I started with the just the ebcm from modulemaster. ABS light stayed on and then instrument cluster started to go crazy.

 

 

 

Message center scrolls between low fuel, battery light and security.

 

Gas guage intermitantly comes one but off most of the time

 

Traction assist light stuck on in off position

 

Check engine light on

 

 

 

Modulemaster said they sent wrong unit so had them send another one. Same problem.

 

 

 

Brought truck to electrical specialist. They said they couldn't get any communication with the any system so they couldn't read any codes. (they have same scanner as dealer) Said dealer best chance but expensive trial and error.

 

 

 

Don't know where to turn next. Is there any way I can narrow down which module might be bad without spending thousands at dealer?

 

 

 

Thanks.

 

You need to gather up some fault codes first.....check the cigarette lighter fuse and then find someone to scan the thing for you.

[edmavalanche]

Having some electrical problems with my 2002 avalanche. It's 2wd with traction control.

 

Long time ago ABS light came on and the pump motor was running. We pulled the fuse to stop the pump and drove until I could afford to try to fix it.

 

 

 

A few months ago, Airbag light also came on.

 

 

 

Took it to dealer, they said something was wrong in airbag but didn't know which part so they recommended replacing all three parts. ($800) They said same about abs, (replace ebcm, pump, etc. $2,200)

 

 

 

Didn't have $3,000 to drop at dealer so I started with the just the ebcm from modulemaster. ABS light stayed on and then instrument cluster started to go crazy.

 

 

 

Message center scrolls between low fuel, battery light and security.

 

Gas guage intermitantly comes one but off most of the time

 

Traction assist light stuck on in off position

 

Check engine light on

 

 

 

Modulemaster said they sent wrong unit so had them send another one. Same problem.

 

 

 

Brought truck to electrical specialist. They said they couldn't get any communication with the any system so they couldn't read any codes. (they have same scanner as dealer) Said dealer best chance but expensive trial and error.

 

 

 

Don't know where to turn next. Is there any way I can narrow down which module might be bad without spending thousands at dealer?

 

 

 

Thanks.

 

You need to gather up some fault codes first.....check the cigarette lighter fuse and then find someone to scan the thing for you.

 

 

 

Thanks. fuses ok, still no communication. Any way to test module when I pull them?

[[email protected]]

Sounds like a class two serial data communication error. I'd start unplugging stuff like ebcm and ICP and TCM and see if the data stream straightens out.

[edmavalanche]

when you say "see if the data stream straightens out", do you mean when I pull the bad module the dash lights will stop scrolling, etc or that the scanner will regain communication?

 

Any other ways to test each module directly?

 

thanks

 

ed

[minibike132]

when you say "see if the data stream straightens out", do you mean when I pull the bad module the dash lights will stop scrolling, etc or that the scanner will regain communication?

 

Any other ways to test each module directly?

 

thanks

 

ed

 

I would recommend a new "electronics specialist" if the trial and error is what was suggested.

 

When he says "straighten out" I would go with that the modules start communicating with the scanner. Unplugging modules will cause all kinds of wierdness including lights blinking and dingers dinging.

 

For that reason I wouldn't pull modules and see if it changes, too many circuits are intertwined, the outcome is too unpredictable. There are splice connections for the module data lines where you can jump critical module communications first then add modules untill the data line goes down that is kind of the low tech way and not very reliable. We would test for the expected voltage on the data lines from each module.

One will show a pull down or up when it should not.

[22zxla]

when you say "see if the data stream straightens out", do you mean when I pull the bad module the dash lights will stop scrolling, etc or that the scanner will regain communication?

 

Any other ways to test each module directly?

 

thanks

 

ed

 

I would recommend a new "electronics specialist" if the trial and error is what was suggested.

 

When he says "straighten out" I would go with that the modules start communicating with the scanner. Unplugging modules will cause all kinds of wierdness including lights blinking and dingers dinging.

 

For that reason I wouldn't pull modules and see if it changes, too many circuits are intertwined, the outcome is too unpredictable. There are splice connections for the module data lines where you can jump critical module communications first then add modules untill the data line goes down that is kind of the low tech way and not very reliable. We would test for the expected voltage on the data lines from each module.

One will show a pull down or up when it should not.

 

[22zxla]

hope you figure it out, because ive had the same issue for a year! 2002 ...wasnt cluster, then i gave up! please post any good results!

[22zxla]

hope you figure it out, because ive had the same issue for a year! 2002 ...wasnt cluster, then i gave up! please post any good results!

[[email protected]]

when you say "see if the data stream straightens out", do you mean when I pull the bad module the dash lights will stop scrolling, etc or that the scanner will regain communication?

 

Any other ways to test each module directly?

 

thanks

 

ed

 

I would recommend a new "electronics specialist" if the trial and error is what was suggested.

 

When he says "straighten out" I would go with that the modules start communicating with the scanner. Unplugging modules will cause all kinds of wierdness including lights blinking and dingers dinging.

 

For that reason I wouldn't pull modules and see if it changes, too many circuits are intertwined, the outcome is too unpredictable. There are splice connections for the module data lines where you can jump critical module communications first then add modules untill the data line goes down that is kind of the low tech way and not very reliable. We would test for the expected voltage on the data lines from each module.

One will show a pull down or up when it should not.

 

 

Are you dissing me and my knowledge of class 2 serial data? I just wanted to know what would happen if he took some things offline like the EBCM. Some were known to do this.

[dlstewart01]

Whats an ECBM.....Oh yeah thats for the brakes...

[[email protected]]

Whats an ECBM.....Oh yeah thats for the brakes...

 

EBCM, fool, not ECBM!! "Electronic Brake Control Module"

[minibike132]

when you say "see if the data stream straightens out", do you mean when I pull the bad module the dash lights will stop scrolling, etc or that the scanner will regain communication?

 

Any other ways to test each module directly?

 

thanks

 

ed

 

I would recommend a new "electronics specialist" if the trial and error is what was suggested.

 

When he says "straighten out" I would go with that the modules start communicating with the scanner. Unplugging modules will cause all kinds of wierdness including lights blinking and dingers dinging.

 

For that reason I wouldn't pull modules and see if it changes, too many circuits are intertwined, the outcome is too unpredictable. There are splice connections for the module data lines where you can jump critical module communications first then add modules untill the data line goes down that is kind of the low tech way and not very reliable. We would test for the expected voltage on the data lines from each module.

One will show a pull down or up when it should not.

 

 

Are you dissing me and my knowledge of class 2 serial data? I just wanted to know what would happen if he took some things offline like the EBCM. Some were known to do this.

 

 

Nope, just saying that it is more reliable and at the same time tons easier to do it all at the splice then to hunt down modules.

[edmavalanche]

So the bottom line is that a scanner is needed to find the bad module and to get the codes back.

 

Not something I can do myself, right? Do I need to go to dealer or can a local shop handle it?

 

Also, if it helps with the puzzle, prior to losing communication, lights flashing and replacing EBCM, dealer had pulled some codes.... I don't think they put the codes on the invoice, only descriptions. (see original post) The closest thing I see on the invoice is 47cvdiag1, 45cvzabslite, and 45cvz....but those are probably just charge codes, right? They charged me $190 just to read the friggin codes.

 

Any ideas?

 

Thanks guys,

[gmtech4]

those are not codes

 

take it to the d e a l e r