3800 need help troubleshooting

[imported_PaceCarBoozer]

One of the GF's friends is having major issues with her '01 Impala, here are the issues that I got from her.

1. Won't start right away

2. Tailights won't work (has brake lights)

3. Needles won't always work (tach, speedo)

4. when she turns the car off, only the engine shuts off, not the electronics. Once they stayed on for 3 hours.

5. Sometimes sounds like there is water running through pipes around the dash (don't think this is a related problem)

This is kinda obviously an electrical problem, but I haven't seen the car to check on blown fuses, and simple stuff like that. Could be an issue with the PCM, but that doesn't explain the tailights, unless that circuitry is running through there. Anyone got an idea????
TIA
CJ

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[smug]

I heard a something a long time ago that those car had ignition switch problems. I dont remeber exactly so I could be completly wrong on that guess.

 

[thebullfrog]

You know my cousin had similar sounding problems on his old 89 Cutlass. Turned out the light bulb in one of the parking lamps was wrong. Caused all kinds of wacked out problems that you would think would have nothing to do with it. Moral of the story- I hate electrons.

 

[Turbocharged400sbc]

[quote name='PaceCarBoozer' One of the GF's friends is having major issues with her '01 Impala, here are the issues that I got from her.

1. Won't start right away

if it's a 3400v6 i have seen many cars do the starts and die....i have tried to diagnose the issue on al and amanda's 01 GAGT

2. Tailights won't work (has brake lights)

check for the dual filament bulbs, are the other marker lights working?

3. Needles won't always work (tach, speedo)

you need to verify that you can collect datta from the PCM but not see it on the dash...i have heard of bad clusters but i've only replaced one myself (fuel gauge haywire)

4. when she turns the car off, only the engine shuts off, not the electronics. Once they stayed on for 3 hours.

check for a prev installed aftermarket alarm/security system....i bet you have the rats nest...

5. Sometimes sounds like there is water running through pipes around the dash (don't think this is a related problem) coolant low with creat a rushing sound through the heater core, but for this reason on most GM's there is a plastic restrictor in one of the heater core fittings to slow down fluid flow to prevent the gurgling... low coolant or the restrictor broke apart

This is kinda obviously an electrical problem, but I haven't seen the car to check on blown fuses, and simple stuff like that. Could be an issue with the PCM, but that doesn't explain the tailights, unless that circuitry is running through there. Anyone got an idea????
TIA
CJ



no problem, now i gotta go to work lol find out more info for me...

 

[imported_PaceCarBoozer]

I hate electronics as well.

James, thanks for all the info, and alot had occured to me, however, the thing that bothers me is that all these problems started all at once. So I would like to figure out what connects all these problems, thats why I was thinking a PCM issue. I don't have the car here, so it will be hard for me to get more information. It's not a huge deal, I just don't want to see this girl get screwed. She has already dumped 600 bucks into his problem with no fixes. She did say that when she got her car back there was a couple gray square plug things on the floor (I assume these were the relays from the fusebox).
Anyways, thanks everyone,
CJ

 

[Turbocharged400sbc]

I hate electronics as well.

James, thanks for all the info, and alot had occured to me, however, the thing that bothers me is that all these problems started all at once. [/b]

ok, you should have included this from the getgo...ok time for some history questions, when did the issue happen, a rainy day? cold, what was the weather like...did she drive any unusual conditions (abnormal long/short trips, potholes/curbing minor fendeer benders from winter etc etc)

any warnings aka any minor quirks noticed in the time before the issues occured (dome light issues, gauge flickering/dropout etc...)

is the wont start right away issue previously existing (aka i've worked on 8 3400 powered cars that randomly out of the blue will take 2-3 crank cycles to start up...aka a bastard of an intermitant problem to diagnose...)



can you scan it for PCM power vs battery? (add a good load and look for signs of voltage drop)

So I would like to figure out what connects all these problems, thats why I was thinking a PCM issue. I don't have the car here, so it will be hard for me to get more information. It's not a huge deal, I just don't want to see this girl get screwed. She has already dumped 600 bucks into his problem with no fixes. She did say that when she got her car back there was a couple gray square plug things on the floor (I assume these were the relays from the fusebox).
Anyways, thanks everyone,
CJ [/b]

relays lol ohhh boy

ok here's what i can believe as feasable...a ground issue would not affect the tailights as these are the same grounds as the brakelights, i know on first gen's it's originally under the driver/passengers seat...we had minor salt/water corrosion on it when we yanked the carpet in the 442...

ask her if the front marker lights come on...if the front circuit works and the rear doesnt, maybe there is a power wire to the rear that was broken by a sharp edge of luggage (or other large objects in the trunk)

a ground issue might affect the gauge cluster...hard to say, a scantool would tell you whether the PCM see's a rpm and MPH signal from the VSS (vehicle speed sensor), if it has it check the BCM/CCM (body/cluster computer module) for the data...modern clusters are serial...new cars are CAN bus...but i digress, you need a scantool with bidirectional controls

when she shut it off and te electronics stayed on for 3 hrs...what electronics were on? (i do hope she payed attention at the time)



she needs to find a shop that specializes in diagnostics...and i wanna know what the gray boxes on the floor are lol



i wish i could help you more...

Regards, James