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Instrument Panel Problem 2004 Envoy

13352 Views 14 Replies 10 Participants Last post by  waltbohlman
I'm new to the group and hope to get some help on an Envoy problem:
2004 Envoy 70K miles Auto, L6, 2WD
Problem was very intermittent but has recently become a hard failure:

At startup:The gauges oil, volt, temp, and fuel remain at zero
The seat belt, antilock brake, and brake failure warning, and
battery warning light stay on.
The shift indicator letters are lit but the indicator does not light.
High beam indicator does not light up when on high beam.
The cruse indicator does not light when cruse is in use.

The Tach and Speedo work fine and no other indicators stay on.
Vehicle runs fine and all other functions work properly.

Can anyone give me an idea what the problem is?

John
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If the tach and speedo were dead also, it could be a communication failure elsewhere that stopped messages from getting to the cluster. Yours sounds like an internal death.

Enay has repair vendors to look at such things. Run a search for "trailblazer gauge repair" and email them with your symptoms. Could be a $100 fix instead of $800 from the dealer.
Sure sounds like a serial data communications failure to me - the tach. and speedo both get their information from discrete engine & vehicle speed signals from the PCM to the cluster. If you want to test this theory, the only other display that is controlled by its own discrete signal is the low washer fluid indicator.
Everything else in the cluster is controlled by serial data. Check continuity on your serial data circuit - between the gray wire into pin B1 of the cluster connector and the purple wire into pin 2 of the ALDL (aka Diagnostic Link, or OBD) connector.
I emailed one of the service providers on eBay and he did not sound as though it would be something simple or inexpensive to fix.
The fact that it was intermittent for several months prior makes me think it may be a connection problem.
vball61 said to check --- between the gray wire into pin B1 of the cluster connector and the purple wire into pin 2 of the ALDL (aka Diagnostic Link, or OBD) connector.
I am assuming that the gray wire connects to the purple wire some where and that to pin 2 of the ALDL connector. Is it supposed to be connected or open? Unfortunately the wiring diagram in the Haynes Manual doesn't seem to match, it shows a gray wire for class 2 data from B1 to something unidentified to a dk green wire to the PCM.

Thanks again for the help
I am assuming that the gray wire connects to the purple wire some where and
Correct, the gray wire at pin B1 of the cluster connector should have continuity to the purple wire at the OBD2 port....there is a splice pack where the modules communication lines meet before going to the OBD2 port.
Problem solved???

I'm new to the group and hope to get some help on an Envoy problem:
2004 Envoy 70K miles Auto, L6, 2WD
Problem was very intermittent but has recently become a hard failure:

At startup:The gauges oil, volt, temp, and fuel remain at zero
The seat belt, antilock brake, and brake failure warning, and
battery warning light stay on.
The shift indicator letters are lit but the indicator does not light.
High beam indicator does not light up when on high beam.
The cruse indicator does not light when cruse is in use.

The Tach and Speedo work fine and no other indicators stay on.
Vehicle runs fine and all other functions work properly.

Can anyone give me an idea what the problem is?

John
You posted this in 2009...did you find a solution to the problem? I'm having the same problem now, in 2011. Thanks.
I'm having the same exact problem but nobody seems to have THE solution to it. On the picture, the four little gauges are out, speed is ok and RPM is ok.
:confused::woohoo:

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I'm having the same exact problem but nobody seems to have THE solution to it. On the picture, the four little gauges are out, speed is ok and RPM is ok.
:confused::woohoo:
Actually there is a solution your panel seems to be getting power, so the issue is more then likely bad stepper motors.
So if I understand, I have FOUR bad stepper motors dead at the same moment ??
:thx
Hmmmm sorry I didnt know they all went out at the same time, def. not stepper motors. I also noticed your ABS and battery light are on.

Did you try what was said at the beginning of the thread? Test for continuity between the b1 grey wire connector (harness on the instrument panel) and the purple wire (OBD2 harness under the dash)
:eek: Not yet. I was hopping to get THE answer to the problem before I go in seeking mode.
:thx
Instrument Panel Fail 2003 Trailblazer

This is my first post, although I have been following this forum for 3 years now.

In regards to the instrument panel fail I had early warning signs that the instrument panel was beginning to fail. At first there was a low battery light that would glow at different intensities and then sometimes not at all. There were no problems with the battery. Then during a snowfall all of the gauges froze at zero, they snapped back into working order after a minute or so. Problem disappeared. A few months later the problem became persistent. Every gauge would be at zero and then bounce back to accurate readings. This is where I should have removed the instrument panel and have had it repaired. :bonk: I waited until the problem appeared at every ignition and took longer to bounce back.

There are a number of repair services on ebay, I used bimmer_hillstore (Best Pixel) in Missouri. They charged $99 plus $15 return shipping to diagnose, repair and return the panel. When they received the panel they tested the unit immediately. They were unable to repair, as the processor was completely fried and had the unit back in the mail that same day. I waited too long and problem was not repairable. I would have loved to have given them my business. They gave me an immediate refund (minus return shipping). Morale of the story send in the panel when you first become aware of the problem and have ruled out fuses.

Priced a refurbished Dorman at $245 +tax at a local automotive parts supplier. There are refurbished instrument panels available on ebay for much less I wasn't brave enough to try. Purchased a GM refurbished part at Community Chevrolet for $381 including taxes. Did this for programming, "American Parts" and warranty reasons.

Make a note of the miles on the odometer before removing the instrument panel. This information will be needed when programming the replacement unit. BTW I was able to drive my TB for 10 days without an instrument panel. :D My husband provided all of the labor on this replacement. We used the a youtube video to help with the instrument panel removal: Chevrolet Trailblazer Instrument Cluster Removal Procedure by: Cluster Fix
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Any solutions

Exact same problem. Anyone find an answer? I replaced ignition switch and cluster. Same issues.
Thanks
Cluster Problem

I had the constantly discharging battery problem...changed ignition switches(2)...replaced gage servo motors...when I changed the motors, I noticed some black corrosion on the back of the instrument panel, on some of the soldered areas. I cleaned these with alcohol and swabs, and reinstalled the panel. All the gages worked properly and the battery stopped going dead. Apparently, if there's any kind of stray current floating around, the computers won't shut down, even after the prescribed up to 20 minutes that is normal. So, the battery drains. Hope this helps.
Cluster Problem I had the constantly discharging battery problem...changed ignition switches(2)...replaced gage servo motors...when I changed the motors, I noticed some black corrosion on the back of the instrument panel, on some of the soldered areas. I cleaned these with alcohol and swabs, and reinstalled the panel. All the gages worked properly and the battery stopped going dead. Apparently, if there's any kind of stray current floating around, the computers won't shut down, even after the prescribed up to 20 minutes that is normal. So, the battery drains. Hope this helps.
Cluster Problem I had the constantly discharging battery problem...changed ignition switches(2)...replaced gage servo motors...when I changed the motors, I noticed some black corrosion on the back of the instrument panel, on some of the soldered areas. I cleaned these with alcohol and swabs, and reinstalled the panel. All the gages worked properly and the battery stopped going dead. Apparently, if there's any kind of stray current floating around, the computers won't shut down, even after the prescribed up to 20 minutes that is normal. So, the battery drains. Hope this helps.
Cluster Problem I had the constantly discharging battery problem...changed ignition switches(2)...replaced gage servo motors...when I changed the motors, I noticed some black corrosion on the back of the instrument panel, on some of the soldered areas. I cleaned these with alcohol and swabs, and reinstalled the panel. All the gages worked properly and the battery stopped going dead. Apparently, if there's any kind of stray current floating around, the computers won't shut down, even after the prescribed up to 20 minutes that is normal. So, the battery drains. Hope this helps.
Hi I had he parasitic draw problem hich drove me nuts for a while then I founf it was the instrument panel drawing current always. I moved the power to the panel so it only got voltage when the motor was running. This helped the parasitic draw but the voltage ,temp and speed ometer were all over the place. So you replaced the stepper motors ,cleaned the board and all worked. I am about to try it. Thanks so much for the post. Walt K3BPP
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