2011 Buick Lacrosse ECM Issues

[busdriver72]

Greetings everyone. I pray y'all are doing well.
I have an issue with our 2011 Buick Lacrosse. I think we've done about all we can, but this is in the hope that maybe y'all can throw something at me that we haven't tried.
The check engine light came on, so I took it in to our local mechanic. I've known him for years and he is very reputable. The scan showed an error that a sensor on the gas pump was faulty. They replaced it. Picked it up. Drove it. Engine light came back. Took it back. They basically disassembled the car...checking wires...running wires...fuse box, etc. Couldn't find anything. Finally came to the conclusion it was the ECM itself sending false info. Defective ECM. No replacement ECMs available from Buick. Order refurbished & reprogrammed ECM from Flagship One. Claimed it was plug and play. It came in...installed it....not plug and play. Keys won't work. He had the needed equipment to do what he should to get the keys to start it. Didn't work. Tried some programming via remote access...didn't work. They put the old module back in and took the car to a Buick dealership. Their mechanics messed with it all day...they couldn't get it to work. Something possibly with the anti-theft?
All Flagship One would advise is that yes, it is plug and play and did we follow the instructions? Yes, didn't work. They said they would some some additional instructions. They resent the same instructions and insisted it was plug and play. They said they could refund me but would have to charge me an $80 reprogram fee. I told the rep that since it was not plug and play and they could offer no solution that i would take this up the chain of command however far I needed to for a full refund. They then offered me a full refund and a UPS return label.
Both my mechanic and the Buick dealership says there is nothing more they can do. The vehicle seems to run ok.
As I was picking the car up a new error showed up on the LED dash...All Wheel Drive Needs Servicing. They hooked up scanner....no code.
Anyone have any experience like this? Just wondering if there is anything else we can try?
Thanks in advance for any help you can offer.

 

[richardnewton]

We were getting periodic (different) messages (e.g. traction control, 3 keys programmed) on the screen of our 2013 LaCrosse.

We saw some posts on the internet (and here) about cleaning some ground contact points (corrosion and excess paint from the factory). You can search for posts with tips if you like; for example:

2010 LaCrosse - Electrical short

Until today I've only read about others having this happen... today it happened to me. I was driving home from work and near the end of the trip, i ran over a small bump doing about 90km/h (about 56 mph). Hardly noticed the bump but what I did notice was my whole instrument cluster going dark...

buickforums.com

Some of the computers and sensors are very sensitive to voltage (and bad grounds) whilst others are more tolerant.

So we cleaned a lot of the ground terminals and connectors to the frame (and maybe around the fusebox). We also cleaned the battery terminals & clamps. I think that was what fixed the problem for us (I don't remember doing anything else). We haven't had those screen messages pop up for years.

 

[Smith1000]

I don't get the AWD needs servicing message, but sometimes get service a stabiltrack message if I have driven through a puddle of water, or snow. Also, it has done this after going through the car wash. It shuts off on its own, eventually. I believe I read once that someone had some false messages popping up, or some type of electrical issue and they found it related to low battery voltage, or possibly, battery terminals that need to be cleaned. When I encounter electrical issues, I start by cleaning the battery terminals real good to make sure everything has good contact and then check the battery voltage and charging level to ensure that is all good and working properly. I some times add jumper ground wires and clean existing ground wires in the engine compartment to ensure all is grounded properly and making good contact. This info is kind of general and may not help you out much. Might be a process of elimination to find the issue.

 

[catrose1972]

Greetings everyone. I pray y'all are doing well.
I have an issue with our 2011 Buick Lacrosse. I think we've done about all we can, but this is in the hope that maybe y'all can throw something at me that we haven't tried.
The check engine light came on, so I took it in to our local mechanic. I've known him for years and he is very reputable. The scan showed an error that a sensor on the gas pump was faulty. They replaced it. Picked it up. Drove it. Engine light came back. Took it back. They basically disassembled the car...checking wires...running wires...fuse box, etc. Couldn't find anything. Finally came to the conclusion it was the ECM itself sending false info. Defective ECM. No replacement ECMs available from Buick. Order refurbished & reprogrammed ECM from Flagship One. Claimed it was plug and play. It came in...installed it....not plug and play. Keys won't work. He had the needed equipment to do what he should to get the keys to start it. Didn't work. Tried some programming via remote access...didn't work. They put the old module back in and took the car to a Buick dealership. Their mechanics messed with it all day...they couldn't get it to work. Something possibly with the anti-theft?
All Flagship One would advise is that yes, it is plug and play and did we follow the instructions? Yes, didn't work. They said they would some some additional instructions. They resent the same instructions and insisted it was plug and play. They said they could refund me but would have to charge me an $80 reprogram fee. I told the rep that since it was not plug and play and they could offer no solution that i would take this up the chain of command however far I needed to for a full refund. They then offered me a full refund and a UPS return label.
Both my mechanic and the Buick dealership says there is nothing more they can do. The vehicle seems to run ok.
As I was picking the car up a new error showed up on the LED dash...All Wheel Drive Needs Servicing. They hooked up scanner....no code.
Anyone have any experience like this? Just wondering if there is anything else we can try?
Thanks in advance for any help you can offer.

I am curious if you resolved your ecm issue. I am looking to replace one which you have to buy refurbished. The website says they need your VIN number to program it for you. Wonder if you had to do this?

 

[busdriver72]

I am curious if you resolved your ecm issue. I am looking to replace one which you have to buy refurbished. The website says they need your VIN number to program it for you. Wonder if you had to do this?

Hello.
It never got resolved. Everyone has researched and tried everything that they can. The error codes still show up, but it runs fine. Sometimes the check engine light comes on....sometimes it doesn't.
Things are getting bad when Buick cannot fix a Buick.

 

[serialusr]

For some reason those back harnesses for the fuel pump control module will pick up a ton of rocks and dirt and sand and crap. It will get into the plugs and cause issues. Also the wiring gets chaffed back there.

 

[serialusr]

Cured my fuel pump sensor code