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Discussion Starter · #1 · (Edited)
Hello,

Have had a 2009 G8 GT for about 3 years. Disconnected battery about a year or two ago and when reconnected the instrument cluster (speed, tach, digital display) was dead and not working. Check engine and anti-theft light would still come on, but not much else. Everything else worked and car ran like normal (radio, remote locks, lights, turn signals, drives, etc.). I found simple issue and fixed it then.

Fast forward to today, and same problem after disconnecting battery, but can't remember what I did to fix it last time. F5 fuse in trunk is all good and everything else in/with the car works.

Any ideas?

Thanks,
Brian
 

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... Disconnected battery about a year or two ago and the instrument cluster (speed, tach, digital display) went dead. Check engine light would still come on, but not much else. Everything else worked and car ran (radio, remote locks, lights, turn signals, etc.)...
Welcome to the forum. "Will Robinson, this does not compute".
 

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Did you do the key re-learn?
 

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When in the engineering mode, does everything appear to illuminate correctly when the instrument cluster test function is selected ? Are the engine coolant temp an fuel gauges working correctly ? Any chance you have some type of trick module plugged into the DLC receptacle ? If so, maybe its got a flaw within it that is interfering with the systems low speed data information for some of the modules.
Or, try to remember/visulize what area(s) you were working in when you solved the problem the last time.
 

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Discussion Starter · #6 · (Edited)
When in the engineering mode, does everything appear to illuminate correctly when the instrument cluster test function is selected ? Are the engine coolant temp an fuel gauges working correctly ? Any chance you have some type of trick module plugged into the DLC receptacle ? If so, maybe its got a flaw within it that is interfering with the systems low speed data information for some of the modules.
Or, try to remember/visulize what area(s) you were working in when you solved the problem the last time.
It will not enter engineering mode, or if it does, I can not see it as driver information display does not work.

Gas appears to work or froze at 3/4 tank. Temp gauge does not work. Tach or any MIL lights within do not work. Speedometer and any MIL lights within do not work. Turn signals work, just don't show on cluster. Everything else works and car drives like normal.

I have a scanner. Just hooked it up. DLC works and communication with all modules is normal, except the instrument cluster. No communication.

Nothing plugged in. Car is really stock minus a tune that has been there for about 2+ years. I would find it hard to believe this is it.

I could be wrong, but I seem to remember it doing the same thing last time, but failed to remember how I fixed.

MIL lights on left side of cluster work (check engine and anti-theft is all i can see come on right now)

Thanks for the continued help and input.
 

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You can always reboot it again {disconnect battery}
 

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...F5 fuse in trunk is all good and everything else in/with the car works ...
F5 fuse in trunk is all good so presuming it was verified both sides have continuity as opposed to visually inspecting the fuse for internal separation. Typically, when the 60 amp fuse on the positive battery terminal blows it causes the radio to malfunction. However, you stated everything else works albeit it may be worthwhile to check that fuse as well.
 

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Discussion Starter · #9 ·
Thank you. I took out, ohmed, and still replaced f5 with a fresh fuse. No luck.

I disconnected both battery cables for about 3 hours. No luck.

I looked at the fusible 60a links and they look intact. As you mentioned, I would think other components would fail if this was the case, but they have not.

I will be doing some more work with the meter in the next few days to see if I have power to the cluster or if power is the issue. . . .
 

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Would be the next step. Posted the instrument cluster pinout and schematic in another thread, Instrument Cluster Pin Diagram. By the way, about how long was the battery initially left disconnected? Were both cables removed?
 

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Discussion Starter · #11 · (Edited)
UPDATED: I think I may have misunderstood Pony Man and updated below.

Initially what led up to the problem was that the negative came loose unbeknownst to me. Was at a store and came back to dead car. It eventually restarted and got it back home. It died again at home and could not get key out. Checked battery and found loose negative cable. Retightened and all was good, minus the instrument cluster.

After this, when I went to "reset" modules to see if instrument cluster would reconnect, I disconnected both cables for about 3 hours while battery charged.
 

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When the F5 fuse in the trunk blows, the remote trunk unlock function on the keyfob fails to operate. Reprogramming the keyfobs are unnecessary.
 

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It would be interesting to find out "what, if anything" changes with the instrument clusters current operation, when the F5 fuse is removed. As if no change, maybe that would indicate that the B+ power never arrived at the cluster. Or even worse, the cluster has failed internally.
 

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Discussion Starter · #14 ·
Removed F5 Fuse

Working on recent comments from Pony Man and Gopherit, I unplugged F5 fuse. The trunk would no longer release with remote nor would the remote FOB unlock/lock. I could still start the car, but this time, no check engine light on dash cluster or no anti-theft light (although the anti-theft may be activated with the remote lock??). Plugged F5 back in and the FOB, trunk, and MIL lights to left of dash worked again, but still no tach, speedo, or information display.

With this little trick, I would have to assume I have power through the F5 and to the instrument cluster.

I unplugged the battery for the night to give this long term option a chance. Will charge battery at same time and retry in the morning.

Fingers crossed . . .
 

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Discussion Starter · #15 ·
Annnndd, no luck. But noticed a few other things:

-filled gas tank and gas gauge did not move. likely stuck at its last memory.
-buttons on steering wheel do not work to control cluster display (which I can't see anyways) or the radio source/volume

Everything else works just fine. As long as I watch my speed and don't care where my mileage is at, everything else works as it should.
 

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If the instrument cluster has to be replaced, try contacting white automotive and media services. Be certain the individual or entity is familiar with the proper protocol.
 

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Discussion Starter · #17 ·
Good News - Problem Resolved

Yesterday, I pulled all the fuses in trunk and under hood while battery was disconnected. No luck.

Today, just before pulling the instrument cluster, I disconnected the battery, pulled and replaced all the fuses at the panel by the drivers feet. I turned the car on to see if this did the trick, but I forgot battery was still disconnected. Key remained locked in the ignition (no way to release it with the battery disconnected). I connected the battery up and the door chime sounded to my delight. Now, all is working again. I couldn't tell you which piece of this allowed for it to reconnect or communicate, but all is well now.

Hopefully this may help someone in the future.

Thank you all for the input.
 

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Good thing it's fixed, but still interesting to know what resolved the issue. Do you figure out why the negative battery cable became loose?
 
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