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.




He found his problem, could maybe help you as well?
Posted at Mon Aug 30, 2010 2: 28 pm
By ofblong, Have Donated
(12) Give Feedback | Votes: 0

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.

Merlin2021
Sep 3, 2010.
Sorry I did not see you had replied to this thread. The o2 sensors are switching (both of them are). However it took a week before the cat test was done (Im too lazy to do it the correct way lol). As soon as the cat test was done the po420 fault came right back on. The o2 sensors were reading the same number but are constantly changing from rich to lean. Neither sensor stays in the middle (.45). The big reason I am leaning towards the cat being bad is because this van has had 2 eaten through head gaskets. First one at 30k miles (under warranty) second one 36k miles later (just outside of warranty). My problem is I didnt have the $$ to fix it at the time so I drove it till it had 95k miles total on the van (30k miles from when it started leaking). I now had the money to get it fixed however we kept driving it until the engine overheated on us. Thats when we took it right in. So for at least 30k miles the Dexcool was most likely leaking into the cat converter. The other thing is the 02 sensors seem kind of sluggish. As in they change value at most 2 times every second. So it could be all 3 items (up and down stream sensors and the cat). It will prob be another week before I can get the cat changed. Place around the corner from me quoted me $300 to change the cat and well thats only $50 more than I can buy a cat and do it myself so I would rather let them do it for $50 haha. Either way what do you think?

Tiny
Ofblong
Sep 7, 2010.
I can see how this " might" cause the issue but I swapped 2 relays (multiple relays are the same on this thing) and the problem didnt follow so I went onto the next thing. As merlin wrote I did find the issue with wiring running across the ac accumulator.

Tiny
Ofblong
Sep 7, 2010.
Down stream sensors dont switch, they remain flatlined, upstream sensors are the switching ones, so look for that behavior in the sensors. Also if oil or coolant is on the sensor wiring, or got into the plugs, clean them out.
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Merlin2021
Sep 9, 2010.
Hmm my downstream sensor is constantly switching just like the upstream sensor.

Tiny
Ofblong
Sep 13, 2010.
What that means is your converter material has lost it's efficientcy. Time for a new one.

Merlin2021
Sep 14, 2010.
Ok finally got the van in (finally had a day off haha). You could hear the cat rattling. Either way they did it for $100 less than I could buy the material myself. Either way now the downstream is pretty constant and the upstream still constantly changes from low to high. Thanks for all yer help.

Tiny
Ofblong
Sep 14, 2010.
Ok good, your welcome.

Merlin2021
Sep 16, 2010.

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