2001 LeSabre electrical problems.

[dovmaor]

My brother's - 50000 miles - fine until......
the car will go into " emergency like " mode - most of the lights in the speedometer , the " Security " light on , AC stops , doors lock opens and the remote ( both remotes)stops , Radio Offs , speedometer and RPM shows OK but all other gages drops to zero . Most important - the battery voltage reading shows 12.9 to 13.3 volts versus the 14.3.. at the battery posts and at the fuse and relay box in and out.
A good kick, road bump or dfront door slam can toggle the situation from good to bad and opposite. This way we shall kick the car to death.
The car saw many GM experts but they are all ( IMHO) are pi..at the wrong tree. My guess there is a groung problem ( or module problem ) at the voltage monitoring point (which probably has the other display functions that show in the instrument panel.)
although unable to pinpoint the culpirit GM people don't share the wiring schematics for the car - help?
Is there such a unit in the front and how do I get it? If unplugged does it lose any software data and needs to be reprogrammed?
Sorry for the long Q but I'm fed up with the local guys here in Israel. The car spent days in central garages without improving one bit.
We are CNC machine tool repair in Israel . If I can't solve this I'm hanging my keys and start looking for a new job. Thanks all - Dovi

[oxygen]

had the same problem once had a bad ground at the fuse box . might
check all relays and fuse blocks make sure they are tight. worth a try anyway.

[polarzak]

Originally Posted by dovmaor

My brother's - 50000 miles - fine until......
the car will go into " emergency like " mode - most of the lights in the speedometer , the " Security " light on , AC stops , doors lock opens and the remote ( both remotes)stops , Radio Offs , speedometer and RPM shows OK but all other gages drops to zero . Most important - the battery voltage reading shows 12.9 to 13.3 volts versus the 14.3.. at the battery posts and at the fuse and relay box in and out.
A good kick, road bump or dfront door slam can toggle the situation from good to bad and opposite. This way we shall kick the car to death.
The car saw many GM experts but they are all ( IMHO) are pi..at the wrong tree. My guess there is a groung problem ( or module problem ) at the voltage monitoring point (which probably has the other display functions that show in the instrument panel.)
although unable to pinpoint the culpirit GM people don't share the wiring schematics for the car - help?
Is there such a unit in the front and how do I get it? If unplugged does it lose any software data and needs to be reprogrammed?
Sorry for the long Q but I'm fed up with the local guys here in Israel. The car spent days in central garages without improving one bit.
We are CNC machine tool repair in Israel . If I can't solve this I'm hanging my keys and start looking for a new job. Thanks all - Dovi

Definately sounds like a loose ground. Regarding your question does the unit need reprogramming if unplugged, I don't think it will. I had the battery out of my car for two days, which would be the same as unplugging the unit, and nothing was lost.

[kok328]

Dovi,

I don't mean to demean or belittle CNC Machinists in anyway but, the necessary skill sets of todays good automotive diagnostic technicians are leaps and bounds above those of a machinist. Please keep your keys and pride intact.

For the most part, the ECM learns your driving patterns/habits by averaging several trips, after the battery is disconnected. All you'll lose is the data that will be re-learned as soon as you start driving again. Oh, of course you will lose and error codes stored in the computer too.

[dovmaor]

Originally Posted by kok328

Dovi,

I don't mean to demean or belittle CNC Machinists in anyway but, the necessary skill sets of todays good automotive diagnostic technicians are leaps and bounds above those of a machinist. Please keep your keys and pride intact.

For the most part, the ECM learns your driving patterns/habits by averaging several trips, after the battery is disconnected. All you'll lose is the data that will be re-learned as soon as you start driving again. Oh, of course you will lose and error codes stored in the computer too.

Thanks all. Which is the module responsible for the instrument panel - could it be the body module? somewhere in the front passenger side. Can you tell me how to get to it ? Also how difficult is it to remove the front dashboard to get to the displays? Thanks - Dovi

[kok328]

Dovi,

I just noticed that I don't know what year we're working with here but see if this will work for you.

Take a look at this for help in removing your dashboard ..
http://www.automotiveforums.com/vbul...d.php?t=429709

[dovmaor]

Right.Sorry- it's 2001. What I realy need is to know where the BCM is located and which wire harnesses go to it.
If anyone can help with this- maybe the front wiring scheme and the physical locathion -be blessed .The local GM people are not very cooprative .
Dovi

[pcmos]

Hi,
Actually most of the documentation you need for this car can be found easily on Ebay. If you want to buy the wiring diagrams and all other service information just go on Ebay and look for "GM ESI" or "GM TECHLINK" software, you should be able to get cheap copies like $15 or so. Anyway, if I had to guess you have a poor connection at the G201 ground post. This is the ground used by the IPM (instrument panel module) and about 6 other devices including the passenger door module and the HVAC blower motor. Based on my diagram, G201 should be located on the console side of the front passenger door frame. Probably where the carpet and plastic panel meet there, not on the door itself but the frame where the hinges are. You should be able to find a connector with a whole bunch of black wires in it screwed to the metal frame. This is only one possible source of the problem but I know on my 2000 I used to get some water intrusion past the door gaskets and down onto the carpet in that general area, maybe this has happened to yours as well but rotted or corroded the ground connector. The instrument panel module can definately be completely disconnected without causing any harm, I have done it. It is very difficult to cause modules to lose their programming, unless you have some voltage spike or other electrical anomoly that causes the eeprom voltage to spike in the module. Recently I installed factory XM satellite radio in my 2000 by using parts necessary from the 2003 model year, I feel like I have mastered the electrical system on this car, including programming and in-vehicle networking systems. I had to run a recalibration of the IPM from a GM Tech 2 scan tool, which you may have to do as well in order to get your HVAC working properly again, but this is just because the actuator motors can fall out of range when they are powered but have lost communication with the IPM, hopefully the IPM will recognize loss of calibration and re-calibrate itself as it should when you disconnect and then reconnect the battery.

[pcmos]

Ok I just found G201 on my 2000, it is very simple to get to. Just remove the plastic runner board on the passenger side, the piece of plastic trim that runs along the floor. This plastic trim you will notice is molded so it follows the corner of the door on the hinge side and meets the bottom of the instrument panel, pull it off and G201 will be right there. this is where the IPM grounds and a number of other devices ground, if your problem is ground, this is probably the culprit. Now that I know where it is, I can see mine has some corrosion on it from my water intrusion problem, i'll bet yours is in bad shape.