Gmc Envoy Speedometer Problems

[CGOHEEN]

My 2003 Envoy's speedometer has started acting eratic. It displays that I am going 70 when I am in park and as I accelerate it goes up. Sometimes it even has that I am goint 120 while in park. What is up with this? Any ideas?

[maxwedge]

Welcome to AF, this is a problem in the head itself and will have to come out for repairs or replacement.

[brian 1]

before you take out the ipc you might want to do this first.inspect pcm ground g108,the ground is located on the drivers side of engine block.This ground is the highest on the engine block and most rearward closest the starter. Remove the ground, clean and secure. Re-evaluate the vehicle.there is a bulletin for this problem.this will only work for vehicles with the 4.2L engine.check this first.

[maxwedge]

Correct, but that ground affects other electronic components and a variety of related symptoms would be occurring.

[robbiejames]

Below is the problems I am having. Do you think the ground would fix my problem since I am have a bunch of problems?

Hi to all. I have a 2004 envoy and just the other day it started to give me some problems and I hope some one can help me out. The problems I am having are with the instrument panel. The problems are as follows:

1. When I get in the suv it says "Unknown Driver" and when I go to push either driver 1 or driver 2 it will load the settings and the seat will go in to the correct position but it will still say "unknown driver".

2. When it says "unknown driver" the ABS light, air bag light, battery light, gas light, and emerg. brake light are all lit.

3. the rpm and mph gauges work but they studder and do not reflect the correct speed, i can come to a stop and the mph will still read 30 mph.

4. the gas, oil, and volt meters do not work.

5. the line under whatever gear you are in does not appear.

6. when you go into the settings you cannot change any of them.


After I drive the suv for about 10-15 minutes it will then jump into driver 1 or driver 2 mode, which ever I tried to push when i first got into the suv, and all the guages seem to work properly, but the battery light then goes to a very dim state and the gas light flashes ramdomly.

I hope someone can help me out with this problem. And have a fix for me.

thanks

Robert

[brian 1]

robbiejames,had to read your thread 3 times?try to help as best I can.cant say if cleaning the ground will fix your vehicle.but clean it anyways and then check again,if it doesn't fix it you will probably have to replace the ipc.I do about 3 a week at the dealer.these problems might be related to the ipc,cant say for sure.you might have 2 different problems.looked at the schematics on the ipc and g108 is the only ground for the ipc.here is the bulletin.hope this helps.post back if you fix it.Subject:Erratic Speedometer Operation or Speedometer Needle Shakes Above 60 mph (96 km/h) (Repair Poor Connection at Ground G108) #07-08-49-027 - (12/04/2007)

Models:2004-2007 Buick Rainier
2002-2008 Chevrolet TrailBlazer Models
2002-2008 GMC Envoy Models
2002-2004 Oldsmobile Bravada
2005-2008 Saab 9-7X
with 4.2L Engine Only (VIN S -- RPO LL8)

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=2042382&pubid=440#ss1-2042382">Condition

Some customers may comment on erratic operation of the speedometer. Others may comment that the speedometer needle shakes above 96 km/h (60 mph).
<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=2042382&pubid=440#ss2-2042382">Cause

This condition may be caused by a loose or poor connection at Powertrain Control Module/Engine Control Module (PCM/ECM) ground G108.
<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=2042382&pubid=440#ss3-2042382">Correction





Technicians are to inspect and repair ground G108 as necessary. Refer to callout 1 in the illustration above for the location of G108. Refer to the Testing for Intermittent Conditions and Poor Connections and the Wiring Repair procedures in SI for more information.

[robbiejames]

Thanks I will try this. So i need to locate #1 from the illustration and just take this loose and clean it? What do you mean by clean just wipe off or do i need to use some contact cleaner or what? please help! Thanks

[brian 1]

just use fine sandpaper or emery cloth.

[robbiejames]

Thanks for the suggestion on how to fix my problem but I hate to have to say it did not work. I know before you said if that did not fix it I may have to replace the instrument panel cluster. Is there anything else that I could do before replacing the cluster? And if not will replacing the cluster fix the problem for sure? If it will fix the problem do I have to have the dealer replace this or can I do it myself?


Thanks once again

robert

[brian 1]

to answer your question,the cluster will probably have to be replaced.I have been replacing alot of these in the past weeks.I suggested cleaning the ground first because if there is a bulletin on something gm wants us to follow that first,and if it doesn't work then start diagnosing it.as far as anything else,that is all you can do.as far as replacing it you can replace it yourself but it will have to go to the dealer to be re-programmed.no other way around it.it's your choice if you replace it or the dealer does.replacing the cluster should fix the problem.good luck

[robbiejames]

Thanks for telling me to check the ground I did this and it did not work. So I guess I will call the dealer tomorrow and see how much this will cost me. I checked around and I did not see a recall on this item but i may have over looked it. Do you know if there is a recall for the 2004 envoy, i seen a recall for the same thing on the 2002 envoy but not the 2004. Well thanks so much for all of your suggestions and help you have helped me when other couldnt and i am thankful for that.

Thanks

Robert

[brian 1]

only thing I can say is maybe,they cover most of the silverado's do not know about evoy and t-blazer.gm changes things from week to week.so if it's not covered it might be later.do not know for sure.

[robbiejames]

Ok thanks I guess I will see what the dealer has to say.

[dhawley]

My speedometer on my 2004 Envoy doing same as above. Also lights were dimming. They found the electrical harness to the cluster shorted out and they are replacing. had to wait 4 days to get the harness. I was 5 days out of warrante and they coverd the 800.00 cost.

[DouglasF]

I have a 2004 Envoy which just recently experienced this same issue. Speedometer at 120 mph +. Where do I find most recent info. on this from GM? How do I find the ground location mentioned? Dealer here in Florida says replace the entire instrument cluster. Everything else seems to work, other than vehicle is no longer level and leans to right. Seems to be related to automatic air shocks??? HAd check engine light but that goes off.