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Guages not working-Light on-ABS,Airbag,Brake light,battery

PHATYELAV

Full Member
Joined
Dec 7, 2002
Messages
337
Location
Highlands Ranch,Co
Guages not working-Light on-ABS,Airbag,Brake light,battery
Speedo and RPM guages do work
ABS light on
Air bag light lit
DIC Shows Unknown Driver
Unable to lock/unlock the doors
unable to roll the windows up or down
Sometimes brake light lit
4wd indicator not working
Unable to use tow haul mode
Radio issues

All this happened when I went over some washboard roads going up to the mountains. It seems to come and go when hitting bumps in the road. Now I notice the black connector into the BCM had melted-The dimmer wire seems to short out to the back up lamp wire. (may have been due to all 4 oh high with HID's mod) I replaced the burnt wires. and removed the all 4 on hi.  Purchased a used BCM and no luck. Bought a new BCM and had my mechanic reprogram the BCM still no luck.  Please help. The mechanic wants to replace the entire wiring harness and I do not have the funds to do that. Nor am I sure that will resolve the issue.

Possible issues?
Bad BCM
Bad Ignition switch
Bad cluster/need re-programmed
Any other ideas?

Please help thank you
Dan O/denver
 
lhswrestler. may want to try this: Now please note I have yet to identify this wire they speak of. But i do have the 8.1l so it may be a bit different for me

To any Tahoe/Suburban/Sierra owners who are experiencing undiagnosed or intermittent electrical problems involving the ABS light/Parking brake light /door locks/ message center/ 4wh drive buttons/ chimes/ etc etc I will identify the simple fix. This fix was suggested to me by a Tahoe owner who was experiencing the "Dashboard Disco" as I was on my 2003 Suburban Z71.

The fix seems too simple to be valid but it has solved the issues on my truck so far.

There is a black/yellow wire that is grounded to the top rear of the engine block on the passenger side of the engine. This ground connection evidently gets compromised by corrosion or oils over time, or it becomes loose. I cleaned the surfaces on my truck and reinstalled the ground. I have not had any electrical issues since doing this.

Regardless of whether you believe this could fix the problems you may experiencing it is certainly worth a try.
 
PHATYELAV said:
lhswrestler. may want to try this: Now please note I have yet to identify this wire they speak of. But i do have the 8.1l so it may be a bit different for me

To any Tahoe/Suburban/Sierra owners who are experiencing undiagnosed or intermittent electrical problems involving the ABS light/Parking brake light /door locks/ message center/ 4wh drive buttons/ chimes/ etc etc I will identify the simple fix. This fix was suggested to me by a Tahoe owner who was experiencing the "Dashboard Disco" as I was on my 2003 Suburban Z71.

The fix seems too simple to be valid but it has solved the issues on my truck so far.

There is a black/yellow wire that is grounded to the top rear of the engine block on the passenger side of the engine. This ground connection evidently gets compromised by corrosion or oils over time, or it becomes loose. I cleaned the surfaces on my truck and reinstalled the ground. I have not had any electrical issues since doing this.

Regardless of whether you believe this could fix the problems you may experiencing it is certainly worth a try.

I'll try it and add it to my list of things for my mechanic to look over.  I'm hoping it's something silly like that since there's only 1k miles on the truck since the new engine was installed and something could come unconnected in that time easily I'm sure.
 
I was finally able to locate the block engine wire they spoke of. Had to find it from under the vehicle. Its primarily black with a yellow/white stripe. I have no idea how I am going to get to it. Also check that ground from the back of the block to the fire wall. Another possible issue is the ignition switch. My mechanic advised they had an extra ignition switch and they tried it with no luck. Also they advised they checked the ground I am concered with and said it was good to go. Not sure how they got to it, but none the less they knew what I was talking about. Other forums advised they just spliced into it (once the correct wire was located and just ran it to the front of the engine on a block bolt and it resolved the issue. hope it helps. please keep the forum updated with your findings.. thank you Dan O
 
Lights and gauges flashing points to a bad ignition switch.
 
Other than the obvious of replacing the ignition switch, is there any way to test for a bad ignition switch? thank you for your help
 
There may be but I don't know how to do that. You could have a short in the wiring harness with the problems that you had but a lot of what you are describing happens with a bad ignition switch.
 
PHATYELAV said:
Other than the obvious of replacing the ignition switch, is there any way to test for a bad ignition switch? thank you for your help

I ran the test that is listed at the bottom of this Technical Service Bulletin.

---------
With the ignition switch in the RUN position, test for battery voltage at the appropriate fuse listed below.

1999-2005  C/K (New Style)  Ignition 0

If battery voltage is present at the fuse, inspect the ignition voltage circuit between the fuse and the transmission for possible opens. If battery voltage is not present at the fuse, replace the ignition switch using the Ignition Switch Replacement procedure in the Steering Wheel and Column sub-section of the applicable Service Manual. Refer to group number 2.188 of the parts catalog for part description and usage.

---------

That's the test I ran...
 
PHATYELAV,

I posted an update on the thread that I started, but I wanted to let you know that my problem was with my Body Control Module.  My mechanic fixed my problem - it was a computer glitch, like when your pc freezes.  He said, "Welcome to the world of computers, that's why I drive an '88 camaro...less to go wrong."    He also said that it could happen again if the issue spawned from when I had the ECM tuned when I got a new engine, but it's impossible to know.  Through his computer he could reset all the gauges, except the speedo and oil pressure gauges so there is still something not quite right there... meaning I may need a new BCM down the road if it happens again. 
 
lhswrestler:

Thank you for the TSB. I tried that and i am seeing voltage at the ign 0. I did have a local shop perfopermance upgrade on the computer but its been that way for awhile. But ya never know
 
Phatyelav, did you ever end up replacing your ignition switch or find another solution?  It's been nearly a month for me without any major issues like we both were experiencing, yet my oil guage still is funky - it is pegged way right and doesn't reset.  My speedo has been fine though.  I'm in the stage of, don't fix it if it's completely broken.
 
Ihswrestler,

Nope to be honest funds have been a little tight lately, I have one mechanic that wants to replace the entire wiring harness (had an issue with the dim switch wire shorting out) But i did notice that there had been an alarm in there also and i know that could cause some issues. either way I want to have a few thousand ready for when I do turn it is to cover the costs just in case.. And well we are not there yet ;). before I take it back to my main mechanic I am goign to take it to a electronic diagnostic specialist that is pretty close to the house. Once I do get it fixed I will let ya know. Unfortunatley after letting my beloved av go for this Yukon XL its kinda been nothing but problems. I think I may get it fixed then sell it to  get an excursion diesel. .who knows I love the truck just not happy with it lately
 
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