Body Control Module question re: 2001 L100
 

RE: 2001 Saturn L100 2.2L L4 DOHC Gas MFI F 61 - about 137048 Miles

We are the original owners and I really hate to junk the car, but can not afford to waste a lot money on a lost cause. The car has manual windows, no cruise, no remote start etc. It's a very basic model with automatic transmission and A/C .

Recently the car shut down while driving on the interstate. AAA towed the L100 to my local repair shop that has been taking care of the Saturn for over 10 years? It shut down because it was out of gas - although both fuel & temp show proper values with the scanner the gauges are incorrect. I am not sure but think he mentioned there were no fault codes. At the time it shut down the fuel gauge read 1/2 tank but the scanner showed 5%, after adding fuel the car appears to be working OK with the exception of the temp/fuel gauges. Owner/mechanic said he thought the gauge problem was related to the Body Control Module and recommended going to a dealer for proper replacement & programming if I want it fixed. I have read on line dirty battery terminals can cause BCM problems so I will clean them today to see if that helps.

Not having accurate fuel/temp is an inconvenience, but I can deal without fuel/temp gauges. My real concern is the problem will continue to worsen to the point the car will not run at all. As long as the scanner gives accurate readings I may even be able to use an android app for fuel/temp levels.


My big question: Is it likely the BCM will continue to get worse until the car no longer runs?

thanks in advance

I don't know if the gauges are run by the BCM or not. But, the easiest way to check that BCM is to locate it, unplug the connector and plug it back in several times and see what happens. The plugging and unplugging will help "sweep" the contacts clean on the plug. On the S series cars, the BCM is located under the passenger side kick panel. Sometimes, cowl drains get clogged up under the wipers and water runs down inside the fender and corrodes the connection. Like I said, I don't know where the BCM is located on the L-series cars, but I'd check there to start with. Maybe Andy will pop on soon. HE knows the L series cars like nobody else here!

Thanks Rubehayseed, I'll check that as well.

Thanks,

ON Edit: I am having trouble getting the glove box out, unable to drop the door far enough to get a screw driver on the screws .

IF this will pull up for you, maybe it'll help. Otherwise, just Google it. That's what I did in order to find this. You'll just have to click the X in the middle about the frigging BMW to get that out of the way.

https://www.google.com/search?q=saturn+L+series+glove+box+removal&tbm=isc h&source=iu&ictx=1&fir=Agh9rf5CUETQoM%253A%252CUWN TFeaMUY60dM%252C_&usg=__PZ_zyn4aGbIt9yHN-aaBulRoSPo%3D&sa=X&ved=2ahUKEwjUs9aFwsfbAhV1IDQIHS KDDeEQ9QEwA3oECAEQSw#imgrc=Agh9rf5CUETQoM:

Thanks, I spent some time and none of the videos I could find were close enough to what I have to help. I did find a comment from a individual that broke his door because he did not know how to get it to drop down . Unfortunately most of the posts on various forums asking for information on how to do it are from many years ago. Perhaps Monday I will call a GM dealer to see what they say, but have serious reservations about spending a lot of money on this vehicle.

This was my thought. Not having a fuel gauge is only an inconvenience, my concern is many have posted their problems kept getting worse.

From the original post: " My big question: Is it likely the BCM will continue to get worse until the car no longer runs?"

It does appear to be changing, today the fuel gauge had the low gas warning light and as I think back, the other day the A/C stopped working for about 20 minutesafter we opened the windows for a while it started cooling again.



ON EDIT:

I had to remove the screws holding the bottom hinge which allowed the door to open far enough to actually unhook it to remove the glove box.
Unplugging the bcm unit connectors had no effect. I did find a web site that lists refurbished for less than #300.00 (www.gmpartsgiant.com) but claims I must get
it programmed. I have read you can use a different bcm but mileage will be off - not sure

The bcm picture: BCM Module located on top of the glove box/

BCM Programming
 

I spent the $300 and got a new BCM, the fuel gauge seems to be working but I am unable to clear the "Security" light and the last time I started it, the air bag & wrench lights came on as well

I used the following procedure but it is not working, regardless of how long I wait the light remains steady on, I also tried just turning the ignition off after 10 minutes - same results:

30 Minute Learn Procedure
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON, vehicle will not start.
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes, the vehicle is now ready to relearn the Passlock™ Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.

I tried it several times, I found many references to using a used BCM but not much on a new one

If you did not have it re programmed prior to installation, all bets are off as to how it will behave. If the security light is on you should not be able to start the car at all. The fact that you can tells me that the BCM probably needs to be reprogrreprogrammed.

Can't half fix a BCM issue unless you get very lucky in terms of the donor car. And if the place you bought it from is pulling it from a junkyard is cleaning it and calling it refurbished with no electronics check then you may have gotten a BCM that went to the junkyard because it was bad

Thanks for the interesting comments.

The unit I purchased was from GMPartsGiant.com and sold as "new" not refurbished. Of course, as you suggest they may be selling junkyard products that have been cleaned up to look brand new. I have no way of knowing for sure, although they do have a A+ listing with the BBB (Genuine Parts Group, Inc.BBB ACCREDITATION SINCE 11/17/2017) Of course, I have no way of verifying the BBB web site either.

****** begin *********

From their Genuine Parts Group FAQ:

Are these genuine OEM GM parts and accessories?
Yes, we specialize in selling only genuine OEM GM parts and accessories.

All parts sold on our website ship from our authorized GM dealerships located all across the US and are the same exact parts found at your local GM dealer.

Why buy OEM parts?
These products are specifically manufactured and engineered to fit your car, truck or SUV just like the original parts that it came with when you first purchased it and include the 12 months 12,000-mile manufacturer's warranty from date of purchase.

******** end quote




So far A/C , fuel + temp gauge, lights etc all seem to work OK

When I first installed the bcm, the security light flashed and it did not start, but after the 30 minute relearn period it started. I plan on checking with a few local dealers to see if any will program the mileage etc. as the new bcm came with 0.0 miles. I did drive it for a little over 1 mile and except for the Solid (not flashing) Security + Service Engine + airbag telltale lights, everything seems to be OK. Well as I wrote the mileage was 0.0, now 1.


I will check with a few local dealers to see if any will set up the mileage etc.

thanks again,

joe

When you ordered it, did you order it for a 2001 L100 specifically, or by part number?

The reason I ask is that some vehicle models and years share the same BCM part number but require different firmware for everything to function properly.

It sounds as though the new BCM came with a default firmware already in there. Never really thought about that before.
So you can do the relearn, then take it and have it flashed to match your car's options, etc.
But the base configuration must be semi-universal enough to allow you to get whatever L compatible car you put it into running.
This may not be true for all BCMs but seems to be from your experience.

Who would have thought GM would do something involving foresight?

Have you tried getting the SES codes read for free at autozone or similar?
They may be nonsense, they may not. Just curious.

I used the VIN number to get the correct part, but the receipt only contains a part number, I did nothing more than install it and do the 30 minute learn process several times. I ran it for a total of 5 miles now and it every thing continues to work OK,

I did not think about taking it to Autozone, but did check it with a cheap OBD2 meter I own and there were no DTC fault codes. Our Saturn L100 has no extra options, it has manual windows, manual locks etc. Basic lighting, A/C and automatic transmission. Perhaps having such a basic model makes a difference.

It doesn't even have the stock radio, we replaced that many years ago. I saw a YouTube video of a fellow that had a Saturn with the same indicators lit and he said the car worked OK that way until he tried put the codes in the stock radio - then the Passlock activated and the car would not start.

It's a tough decision at this point because everything appears to be working OK. If AutoZone is free, that may be an option to consider.

If the radio install affected passlock, he must have tapped into the ignition circuit, changing what the BCM was seeing.

AutoZone will read no more trouble codes than your reader. It is impossible to know if the air bag system is disabled as the light indicates without using a more sophisticated scanner to read the srs system for codes. If any codes that come up are body codes, you don't know if it is due to the fact that the BCM needs reprogramming or if the issue real.

Reprogramming it to match your car should leave you with a properly operating BCM

Thanks for the comments, we may wait a while to see what happens as we are also considering buying a new car for my wife and I would then get her car. The only problem with that is I like the physical size and layout of the L100 better than her Cruze.

I called a local GM dealer, I was told I could not get the mileage programmed because the BCM module must be programmed before installing into the vehicle. They recommended I have the car towed to the dealership and buy a new body control module from them and they will program it before installing it. They did say they can re-program the one I have now - it will take 1.5 hours of labor but they don't know if it will work when finished. I do not understand why they said I must have it towed when it drives ok. The dealer also said because the mileage is off I can not get a new registration.

I also called the local garage, they told me it can not pass inspection with the check engine light on, and if the mileage is really different it will throw up a red flag on the emission control tests. I am going to drive there this afternoon and let them hook up their scanner to see if they can determine the fault codes. At any rate, the way it is I should still be good for almost a year.

I refused to buy a new BCM from the dealer, but I may try another dealer.

Mileage programming is a touchy subject to many, especially dealetships. They cannot afford to get caught up in even one odometer fraud scandal or anything that remotely resembles one.

So the policy becomes "we only program mileages into bcms we sell after we verify the paperwork and see it is legit."


​​​same deal wih some years of ion dashes. They will sell you a brand new one and program the mileage. Bring them a junkyard dash to reprogram and they want nothing to do with it.

I would not be surprised if mileage programming must be the first sep
But there has to be factory reset option somewhere to revert it back to a virgin state.

Many independent mechanics have the electronic tools to do the bcm flash.

The question is how do get back to the virgin state.

You may widh to contact the vendor you purchased it from. They may know the details.

thanks again,

I called a Buick dealer and their service department had a friendlier attitude, said they would re-program it for $99 - best part was she knew what I was talking about, did not keep running back to talk with a tech.

Later I took the Saturn to the shop that does the state inspections, the owner said not to worry about the mileage on the odometer if they can not fix it because as long as the odometer is working he will pass it. He told me I could put the mileage at the time it was reset to 0 the door jam. Apparently years ago they did that all the time after they changed out speedometers. He told me he also has records of previous emission & state inspections .They also hooked up their Snap On scanner and found no faults, the warning light was for oil change, apparently the new bcm does not accept the reset - it goes out for a while then comes back.

After I got home I put the old BCM in and took a picture

I now have record of the mileage. I think everything is OK, probably would not even need to get it programmed but already made the appointment

I looked and according to PA DMV law, there is a place where you can acknowledge the odometer error on the title transfer, and enter the correct mileage. I forgot what number it gets, think it might be #2 for error and #3 for unknown mileage. Also, I have read a post from individual that got junk yard bcm mileage set properly during programming. At any rate, I will find out - too busy next week but the following week I can get it in for programming, until then I will keep using it.

When we were looking at the Buick dealer website for the service phone number we noticed they had new base model Buick Encores for less than $20G with all the special discounts/rebates etc. so maybe the wife will test drive one to see if she likes it. I like the old Saturn better than her Cruze but it may be time for me to change.

on edit: I do believe within the next year we will stop using the Saturn, probably send it to the junk yard.

I had documentation with the odometer reading from the last Pa State inspections along with a photo of the odometer when the old BCM was removed. Faulkner Buick/GMC in Harrisburg Pa programmed the new BCM and added the previous miles to the new BCM. Now everything is good again and it was only $95 + tax. Saturn seems good now, everything looks OK, including the odometer and all the gauges are working correctly again.

It was the first time I was at Faulkner Buick/GMC in Harrisburg and I was really impressed. My total cost for BCM replacement was about $400, and I am planning to keep the old Saturn a while, but we may now trade my wife's 2011 Cruze in for a new car for her.

So all dash lights out and back to normal?

Good to hear

Yes, everything is normal, including the odometer. I was a little giddy, felt like I got my Saturn back.

I was a little worried after a 4o minute wait so I asked them about the progress and they said the programming was done, they were waiting for the hand washing to finish up. Not only it was fixed , it was clean as well. Even though I hate ONStar, we are tempted to buy a Buick Encore from them, our experience with the service department at Faulkner Buick/GMC was really pleasant .