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Old Sep 18, 2006 | 11:47 AM
  #1  
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Default Went bonkers

While driving last night my PCM attempted several resets (tach and speedo going from min to max and then slowly back down) and several of the warning lights (ie. ABS, check-guages, etc.) blinked like a christmas tree on the dash. Electrical power fluctuated wildly, maybe at one of the firings of 8 and engine power as well. Pleanty of "grinding" sounds like when there's low traction.

After "Christmas" was over on my dash it started up again intermittently so I pulled over (of course) and let the car sit for a bit. Started it up and everything was fine. Drove home with no problems.

Can the PCM "hiccup" like that sometimes?? I have had Hypertech PPIII and Vince Crane (to eliminate the skip-shift) programmed-in but it's been 3 years since I did so. I did move from an altitude of 7200 ft. to 5800 ft. just recently. Everything seemed connected well and the belt was fine.

Also, what is the solution to the rear-defog/power seat fuse dying occasionally? Do I just replace the fuse? I believe it's a common problem, as they're both linked. Using the rear-defog button it goes out and then the seat and rear-defog are dead for about 2 minutes.

Mike

pls.email response to mikecronis@mikecronis.com
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Old Sep 18, 2006 | 08:35 PM
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Do you have a '99?
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Old Sep 19, 2006 | 01:13 AM
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'99 Firehawk, yes.
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Old Sep 19, 2006 | 06:00 AM
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99's are known to have problems with the wiring in the guage clusters causing the guages to do weird things like that. It's not a pcm problem. I don't know about the grinding sound though or the defog though.
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Old Sep 20, 2006 | 11:07 AM
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Also either the battery/alternator that are on their way out can cause similar problems. Keep an eye on your voltage gauge.

Rob (Bad30th)
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Old Nov 8, 2006 | 10:08 AM
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I am having the same problem with my '02 WS-6. Guage cluster appears to reset several times same, as when key is first turned on, and engine power fluctuates and headlights flicker a bit, but don't go out completely. This doesn't seem to happen when the car is sitting still, only when driving. Last night the guages died for about 5 miles (all resting as when key is off), the backlight was still on and cruise worked until power came back, the gas pedal was kicked back like when TCS engages. It appears to be a power problem, the volt meter reads approx. 14V, but I am still using the original battery. Has anyone found a cure? mikecronis, did you find the problem?

Another post I found:
https://ls1tech.com/forums/pcm-diagnostics-tuning/593876-really-odd-electrical-problem.html

Last edited by rileyl; Nov 9, 2006 at 10:21 AM.
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Old Nov 8, 2006 | 12:52 PM
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I am fighting the exact same issue with my 01 SS. My voltage meter on my Passport 8500 goes from a steady ~14V, to flickering thru the whole 13V range. The cars dash will cut off and on in the same manor that the original poster describes. I have a relatively new battery in my car. This morning, the car started up and you'd never know that it had an issue.
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Old May 9, 2008 | 12:09 PM
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Anyone have some answers to this problem? I recently started to encounter the same problem in my 01 SS. I have cam, lt, ory. New battery and starter. Got the car back from the shop getting the mods above installed. Car ran fine for the first 100-200 miles. I then swapped out my LM exhaust for a Hooker and then noticed the problem the next day. Went on a quick run to the store. When I went to leave, the car started right up, but quickly stalled out. Started right back up and seemed fine. Got on the road and notices the gauges all started going crazy. Pulled over and shut it off. Waited a few minutes and it started right up. Heading down the road again and the gauges started doing the same thing. This time, the car backfired and died on me. Pull it over and waited a few more minutes and it fired up again. Drove it home with no further issues...

Drove the car the next day and did not have any problems with it. I then decided to drive it to work today as we are all planning a trip to the track after work. Car drove fine for the first 10-15 minutes and then the radio shut off and I noticed the gauges were going crazy again. This time it only lasted for maybe 5 seconds and the car never died. I was able to get to work (another 10-15minute drive) without any additional problems....

Any ideas what is causing this? I checked the battery connections and the ground, but they appear fine.... Should I not risk going to the track tonight?

Thanks,
Kevin
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Old May 9, 2008 | 02:57 PM
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Check the grounds on the back of your driveside head
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Old May 9, 2008 | 03:01 PM
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Originally Posted by transam69230
Check the grounds on the back of your driveside head
AS in the motor to chassis ground?
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Old May 9, 2008 | 03:37 PM
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No the ones from the head to the wiring harness. I just had the same issue sorta of. My car wouldn't start at all though. The gauges were all jumpy, and the the car wasn't getting spark. Turned out one of the ground wires got pinched when i put my motor in and broke off.
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Old May 9, 2008 | 03:39 PM
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Originally Posted by transam69230
Check the grounds on the back of your driveside head
Sorry, I wasn't aware of any grounds on the driver's side head. Can you tell me where to look? Can I see it from the top looking into the engine bay?

Also, as a quick fix, I was going to try to add a new ground from the battery to the front passenger side of the block. There is a nice little bolt hole there. Any thoughts on this?

Thanks again,
Kevin
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Old May 11, 2008 | 04:06 AM
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Mine was doing the same thing.. I found out that the little bolt covered by a red plastic was loose and was not getting contact,its on top of the driver side headlight.
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Old May 11, 2008 | 09:05 AM
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Originally Posted by BuBbABFP
Mine was doing the same thing.. I found out that the little bolt covered by a red plastic was loose and was not getting contact,its on top of the driver side headlight.
That is exactly what mine problem was as well. I found the bolt on the driver's side right next to the fuse boxes under the red plastic cap was just slightly loose. Tightened it up and have not had the problem since.

Thanks for the feedback!!!
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