Mechanics

GAUGES TURN OFF AND ON AMONG OTH

2002 Oldsmobile Silhouette

Electrical problem
2002 Oldsmobile Silhouette 6 cyl Front Wheel Drive Automatic 98000 miles

Ok while driving it takes about 30 miles down the road and then the gauges act erratice. Sometimes just one sometimes all. Then the radio will shut off, gauges shut off and the BCM will ding at me for low fuel. Then all the gauges will come back the door locks reset themselves (by unlocking then locking once) and the radio turns back on. Sometimes after this happens the radio shuts off imediatly after the key is removed other times it doesnt shut off when the door is opened (but the lights come on) (so I have to remove the radio fuse then reinsert and it fixes it). It started out every half mile but I have since replaced the BCM, Ignition switch, battery (it was 9 years old), and the alternator (was giving inconsistant readings on my volt meter which is now giving me consistant readings). Every time I change something it gets better to now it only happens after 30 miles and then doesnt do it again for another 30-40 miles.

I have removed the IPC and checked all the wires going into the cluster and found nothing wrong. I am trying to figure out how to check the passkey system so that I can verify if the pk3/theft lock is bad or not as I dont want to change it unnecessarily. The other items I replaced were all bad but didnt fix the origional problem.

sorry I did not see the edit button before now lol. Also the DTC loses power as once I had my Equus scanner connected to it recording live data and it lost connection with the pcm when everything else lost power and went awry. Sorry forgot to add that I have checked the body grounds under the hood and then the ground lug under the drivers side between the steering column and the cluster as well as the ground on the passenger side by the blower. When these problems occur the security light stays on until I shut the vehicle off wait for it to cycle through all the messages that display besides security (like rear hatch ajar, door open, battery power etc). As soon as those are done van starts right up. The engine does not stop running when this happens either as I will have the cruise control on and the van keeps that speed.

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Ofblong
August 16, 2010.




Some GM's have a plug under the driver's seat, and not for the power seat, it would plug into one coming into the vehicle from outside, if you have one, unplug it and inspect for corrosion and damaged pins, this may cause all your symptoms too.

Merlin2021
Aug 25, 2010.
Yeah there is no plug under my seat for that. The only thing I found (finally found that I was going to the wrong wire on the strip for the DIC lol) was there was a BUNCH of dexcool in the compartment with the PCM. I took a rag and cleaned out as much as I could and then used a blow dryer to dry it off. My guess is it got in there when the engine overheated and blew coolant all over the engine compartment (thus why I went and had the manifold gaskets replaced). So far drove it 10 miles and nothing has happened. Then again its not 90+ degrees out and only 72F. If and when it comes back I will take it into the dealership and have them run a tech 2 on it and see if they can at least tell me which part is bad. The cd player in the radio quit working as it wont read a single cd (started not reading them before I started ripping everything apart). So it might be the radio but the radio eye might just be dirty so I dont know. I am leaning more towards the IPC but again without the expensive tools to verify it I am not gonna just change it out lol.

Tiny
Ofblong
Aug 25, 2010.
You MUST unplug the wet connector and see if water got insde the plugs, dry them off! You can also remove the plugs at the IPC and inspect both the plugs and the IPC circuit board, many times just unplugging and re plugging fixes problems, GM even sent out a tech bulletin to the dealerships to do just that.

Merlin2021
Aug 27, 2010.
I unplugged both the blue and white connectors and no water got inside them. Did that when I cleaned out the compartment.

Today the van WOULD NOT start. I could hear the fuel pump turn on but I didnt get that " click" sound of it wanting to start. The radio wasnt on so I unplugged it and the van started. All the gauges were completly eratic. I pluged the radio back in and it did not turn on until the instrument cluster stopped doing its dance. Then it would turn back on. I unplugged the IPC and I no longer get the low fuel ding. Though now the radio wont turn on because of how its tied to the IPC. Unplugging and plugging the IPC connectors back in makes it not do any funny stuff for about 1/2 mile then it starts right up again. I am getting 13.6 volts with everything on at the orange and black wires (hot and ground) on the IPC plug so its got plenty of voltage. Plus I just noticed today that the Odometer is not keeping miles anymore. SSSOOO I am gonna have the IPC sent out to be refurbished as its $100 cheaper than buying a new one and having it programed at the dealership.

Tiny
Ofblong
Aug 28, 2010.
Let me know how that turns out!

Merlin2021
Aug 28, 2010.
Finally found the problem. The harness coming out of the PCM goes down under the air duct and to the ac accumulator. There was about 100 ish wires in this wire loom (I am estimating but there sure were a ton of wires) and most of them were shorted against the ac accumulator. Holy cow is that alot of work to repair all those wires. I didnt notice it because it was hidden on that side.

Tiny
Ofblong
Aug 30, 2010.
That'll do it! Tough finding the little buggers eh? Nice work.

Merlin2021
Aug 30, 2010.
Yes very tough especially when there are so many that are so small lol. It seems to have fixed my po420 fault as well but only time will tell on that one. I havent checked to see if the cat test has finished yet or not lol.

Tiny
Ofblong
Aug 30, 2010.
You can recheck to see if the o2 sensor is now switching between rich and lean.

Merlin2021
Aug 31, 2010.
My 2004 Silhouette had this problem any time the outside temp went over 26 degrees centigrade. After driving a short while, guages go nuts, traction control, check engine and other lights activate, speedo gets jumpy and the engine stalls.
It will restart almost right away only to repeat the problem shortly.
I traced the problem to the ingnition relay in the fuse/control box, right corner under hood. ( New relay did not help).
High underhood temp, + battery heat ( right under the box) are combining to cause this relay to open temorarily. Driving with the plasic cover removed has cured this hot stall problem. Its never an issue in cooler temps. ( Some models may have less accessories running thru this relay, creating less heat, and so may not have this problem). Venting the cover also helps. I've done this recently.
I would suspect the Venture and Montana will also experience this problem. Hope this helps. Sparkii
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Tiny
Sparkii
Sep 1, 2010.

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