Greetings. I have a 2001 MC SS and it has more problems then a virgin on valentine's day! Here is the list.

1) Instrument lights do not turn on. The Exterior lights turn on when it gets dark, as they should. However all of the cluster lights do not turn on. Once in a blue moon, they will. But I can find no reason as too why. The light switch/ interior dimmer does nothing.

2) Low gas mileage. I get 20MPG. I have had this car since new. I have never gotten below 24MPG. That was when I had 4 subs in the trunk, and another 50lbs of amps and caps. I have removed ALL of that stuff, and now I get poor MPG. I dont' even know where to start troubleshooting that.

3) The "Low Tire Pressure" idiot light is always on. I have filled the tires to the correct specs, and it still comes on after I reset it.

4) The option to reset the "Low Tire Pressure" is not available in the radio's SETTINGS menu. I must reset it by pulling the negative battery terminal. About 1 day later the "Low Tire Pressure" light comes back on.

5) It looses power during left turns. If I am stopped and making a 90 degree left turn some times it will hesitate and not want to go. I assume this is the CV's fault.

6) When I go to WOT hitting redline, the transmission will not up shift. If I floor it, no matter what gear, and keep it at WOT the car will not shift into the next gear. It will remain at redline.

7) I noticed before the transmission was slipping. However this does not seem to be an issue anymore.

I have had regular oil changes. I had the trans flushed when it started slipping. The most pressing to me is the MPG, and the interior lights. The car has 125k miles on it. Aside from a K&N air filter, the car is bone stock.

Any and all suggestions, ideas, are welcome! Thanks!

 

[:@]Matt, the reason you are having all these problems
is that you've been `BAD[:@][IMG]local://upfiles/714/20B8548E55884DFCABAD17B41DFED3BA.gif[/IMG]

The forum has several great GM Tech's as members, but they aren't on
everyday. Be patience & I'm sure you will get some idea's or
answers to your many Monte problems. Good Luck`Space

 

I know with a few other GM vehicles, these are all common symptoms of a BAD GROUND somewhere. Check all your grounds in the engine bay, they pull the negative battery cable and reset the computer. Also, If your battery is old, REPALCE it, old batteries can cause a ****load of electrical problems!

Jason

 

Here's the steps to clear the Low Tire Pressure message when the radio won't.

It is the first paragraph on pg 6-45 of the owners manual. You can find a copy here: http://mymonte.com/tech/manuals/2000montecarlo.pdf

Basically have the key in the on position... you can do this with the car running as well.

Pull the head light switch out 1 click so the parking lights are on, then turn the button clockwise till the dome light comes on and then back so it turns off. Do this a total of 3 times. with about a 1 second pause between each one.


As for some of the othe problems, it might be a bad PCM. The PCM controls fuel flow and transmission shifts. It *might* control the interior dash lights automatically turning on and off being tied in with the auto lights that turn on at dusk.

I'd run the last idea past a dealer and see what they think... If they agree, see if you can get them to reflash it and if it fixes the problem then pay for it. You have to be on good terms with your dealer or they have to be really cool.

 

Thanks everyone for the replies.

I have replaced the battery with an Optima Yellow Top battery. It is the one electrical system I trust on this car.

As for the PCM I will have to give that a try. Does it also control the settings in the radio? The reset tire option was in there before. How long will the flash take the dealer to do? Can I expect them to do it while I wait? These cars have sooooooo many wires, how can I troubleshoot a improper ground?

Thanks again for any and all comments and advise!

Matt|ttaM

 

Well I tried the reset tire pressure trick with the light switch. I tried for 10 min to no avail. Any other ideas? Should I deflate the tires to 0 PSI and drive it to work?? That would show the computer what "low tire pressure" really means!!

Does anyone think the left turn power loss could be related to the electrical issues? I also get the Service Traction Control warning light. That light only comes on when the car makes a turn that 'disagrees' with it.

Matt|ttaM

 

Space, how did you know I had been bad latly?

 

The PCM shouldn't have a direct relationship with the radio like that but it is possible. I am looking into this right now and being a shadetree mechanic I don't exactly have the inside skinny.

I will have more info in the next few months in general as I'll be ordering the $120 copy of the mechanics manual for my car. No more Haynes obscurities or write outs.

 

Sounds like your dimmer/headlight switch is shot... fairly common problem. You'll probably need to replace the headlight switch assembly. There is an off-chance it could be the BCM acting up, but it doesn't sound like it.

Things to look at: Clogged Cat, Clogged Injectors, Clogged Fuel Filter, Bad Fuel Pressure Regulator, Bad Spark Plugs, Bad Plug Wires....

I saw you posted you get "Service Traction" messages as well.. This usually indicates you have a bad wheel hub speed sensor. You'll need to get someone with a Tech-II to scan and tell you which hub it is...

Sounds like the BCM is missing the TPS option so it doesn't show up in the Radio... A Tech-II is needed to check and/or reprogram. DOn't remember off-hand if you can add that RPO to the BCM without getting a new BCM


Good luck...

BBEngineer

 

Wow, thanks for the in-depth reply. I will have to find out more to troubleshoot. Will the Tech II tell me if the Cat is clogged, or if the injectors are dirty? Should I just take this thing to the dealer? Or will I get comparable service at a different mechanic. (If anyone knows a good dealer or mechanic for these cars in the DC/Baltimore area, that would be helpful.

Does anyone know if there is a FSM (Factory Service Manual) online anywhere? Thanks again!

Matt|ttaM