Chronic no start issue 2011 Buick LaCrosse CSX

[2011 LaCrosse owner]

January 2024 I purchased a 2011 Buick LaCrosse CSX from a private party with 26,300 miles. There were two issues that needed attention per my local Buick dealer: the amplifier and passenger rear view mirror motor which adjusted the position of the mirror were faulty. The dealer indicated the parts were no longer available.

After a couple months I located a local auto repair shop which specialized in electric/electronic issues and they were able to secure a replacement amplifier and mirror.

In June 2024 at 28,676 miles, I attempted to start the car with foot on brake and pressing start button, nothing happened. Not knowing what to do I placed the FOB closer to the start button and finally in desperation I pressed the FOB lock button, heard a loud click in the driver door and the car started. Thinking it was a low battery in the FOB I replaced it.

In January 2025 at 35,166 miles I started getting momentary flashing messages in the DIC "Service Supension System" and "Service AFL Lamp". At that time I returned to the auto repair shop and we cleared the history of many codes and only BO223 and BO300 returned.

I continued to drive the car, enjoying its comfort. However, I still continued to have momentary times when the car would not start. I would get various flickering messages on the DIC from "Service Suspension System, Service AFL Lamp, Service Parking Assist, Open and close driver's window and more." After additional non start moments, I returned the car to the auto repair shop (May 29, 2025, 39,748 miles) and they repaired a couple grounds which they indicated would cause low voltage which would trigger the DIC messages. On a subsequent visit they replaced the battery due to what they described as internal short. After a few days of road test they returned the car.

But the issue continued. Finally in July 9, 2025 at 41,383 miles I returned the car and this time they indicated there was alternator with low voltage at times and replaced the alternator. Upon return the car worked flawlessly for 2 solid weeks. I was beginning to have confidence I could use the car without fear of being able to return home.

Then the problem returned. I could no longer lock/unlock the car with my thumb pressure, I had to use the key. When the car would not start, I would sometimes press the FOB lock button, hear a loud click in driver door and the car would start. Other times there would be a continuous soft clicking sounds from the engine compartment but nothing would start.

For 3 weeks the car has sat in the driveway, when I last tried to start it, there were the continuing soft clicks from the engine compartment but the car will start. Now there are no noises. Yesterday, I attempted to slow charge the battery at 2 amps. When I placed the negative cable on the ground post, the horn started blaring.

In my last conversation with the auto repair shop, they are at a loss as to how to proceed.

I would appreciate any advice you may have to offer. It seems to me there is a malfunction between the FOB and some sensor in the system that is faulty and needs to reset for the car to start. One additional item. When the car fails to start, but finally starts, the DIC message always returns to the MPG message even though I have it set to Odometer/Trip 1 setting.

Thank you for reading this lengthy dialogue.

 

[Anthony Cipriano]

January 2024 I purchased a 2011 Buick LaCrosse CSX from a private party with 26,300 miles. There were two issues that needed attention per my local Buick dealer: the amplifier and passenger rear view mirror motor which adjusted the position of the mirror were faulty. The dealer indicated the parts were no longer available.

After a couple months I located a local auto repair shop which specialized in electric/electronic issues and they were able to secure a replacement amplifier and mirror.

In June 2024 at 28,676 miles, I attempted to start the car with foot on brake and pressing start button, nothing happened. Not knowing what to do I placed the FOB closer to the start button and finally in desperation I pressed the FOB lock button, heard a loud click in the driver door and the car started. Thinking it was a low battery in the FOB I replaced it.

In January 2025 at 35,166 miles I started getting momentary flashing messages in the DIC "Service Supension System" and "Service AFL Lamp". At that time I returned to the auto repair shop and we cleared the history of many codes and only BO223 and BO300 returned.

I continued to drive the car, enjoying its comfort. However, I still continued to have momentary times when the car would not start. I would get various flickering messages on the DIC from "Service Suspension System, Service AFL Lamp, Service Parking Assist, Open and close driver's window and more." After additional non start moments, I returned the car to the auto repair shop (May 29, 2025, 39,748 miles) and they repaired a couple grounds which they indicated would cause low voltage which would trigger the DIC messages. On a subsequent visit they replaced the battery due to what they described as internal short. After a few days of road test they returned the car.

But the issue continued. Finally in July 9, 2025 at 41,383 miles I returned the car and this time they indicated there was alternator with low voltage at times and replaced the alternator. Upon return the car worked flawlessly for 2 solid weeks. I was beginning to have confidence I could use the car without fear of being able to return home.

Then the problem returned. I could no longer lock/unlock the car with my thumb pressure, I had to use the key. When the car would not start, I would sometimes press the FOB lock button, hear a loud click in driver door and the car would start. Other times there would be a continuous soft clicking sounds from the engine compartment but nothing would start.

For 3 weeks the car has sat in the driveway, when I last tried to start it, there were the continuing soft clicks from the engine compartment but the car will start. Now there are no noises. Yesterday, I attempted to slow charge the battery at 2 amps. When I placed the negative cable on the ground post, the horn started blaring.

In my last conversation with the auto repair shop, they are at a loss as to how to proceed.

I would appreciate any advice you may have to offer. It seems to me there is a malfunction between the FOB and some sensor in the system that is faulty and needs to reset for the car to start. One additional item. When the car fails to start, but finally starts, the DIC message always returns to the MPG message even though I have it set to Odometer/Trip 1 setting.

Thank you for reading this lengthy dialogue.

Hey there. I read your post, and that sounds like an absolute nightmare. It's totally understandable that you're at your wit's end, especially after throwing so many new parts at the problem. A lot of people have been in your shoes where it feels like you're just chasing a ghost in the electrical system.

Based on everything you've described, all the crazy random stuff - the no-start, the flickering dashboard messages, the loud and soft clicking noises, and especially the horn going off - it all screams one thing: a massive electrical gremlin, most likely a parasitic drain or a bad connection somewhere.

A parasitic drain is like a vampire sucking the life out of your battery, even when the car is off. This explains why your battery keeps dying and why you're getting all those low-voltage messages on the dash. Everything from the infotainment system to a faulty relay can cause this.

The loud clicking sound from the driver's door when you press the fob is a huge clue. It's the sound of a relay trying to engage, but it's not getting enough power. The "soft clicking" you're hearing from the engine bay is probably another relay doing the same thing. The car's computer is smart enough to know that it doesn't have enough juice to start, so it tries to engage the relays to get things going, but they just can't handle it.

The horn blaring when you put the negative cable on the ground post is a major red flag. That means there is a short circuit somewhere, and you should not try to charge the car again until you find it.

Honestly, it sounds like your mechanic is in over his head. This isn't a simple mechanical issue that can be fixed with a new alternator or a new battery. This requires a professional who can perform a full parasitic draw test. They will have to go through the car's electrical system, circuit by circuit, to find the one that's draining the battery. It's a very tedious process that requires a lot of patience and expertise, but it's the only way to get to the bottom of this.

 

[2011 LaCrosse owner]

Anthony:

Appreciate so much your response. I felt this Buick Forum might yield a response but after nearly a week and over a couple hundred views and no responses, I was getting discouraged.

While your news is not good, at least it makes sense. I had been having it serviced by what is known as one of the better electrical auto repair places in town.

Do you have a suggestion as to where I should go? While I don't normally like working with Dealers. Is it probably my best option? Since it takes time I'm sure it will be considerable more expense, but it if can be repaired, the car has relatively low miles. I am a long time Buick owner and normally get up to 200,000 miles on them.

Again, appreciate your taking time to respond. Any additional help would be greatly appreciated.

Keith

 

[Anthony Cipriano]

Anthony:

Appreciate so much your response. I felt this Buick Forum might yield a response but after nearly a week and over a couple hundred views and no responses, I was getting discouraged.

While your news is not good, at least it makes sense. I had been having it serviced by what is known as one of the better electrical auto repair places in town.

Do you have a suggestion as to where I should go? While I don't normally like working with Dealers. Is it probably my best option? Since it takes time I'm sure it will be considerable more expense, but it if can be repaired, the car has relatively low miles. I am a long time Buick owner and normally get up to 200,000 miles on them.

Again, appreciate your taking time to respond. Any additional help would be greatly appreciated.

Keith

Hi Keith. Well, if the place you're going is good, and they can't find the issue, the dealership may be the better option. The issue may be something they've had to repair in the past. And in that case, they'd know exactly how to fix it. Maybe stop by your local Buick dealer and explain the problem. If they're not familiar with it, ask what it would cost for a diagnosis. It might be a good idea to ask what that would cost if they CAN'T find the issue.