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2012 Lacrosse A/C not working

wmwalton

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New member here.
I have a 2012 Buick Lacrosse with the 4cyl E-Assist engine.
Last fall the A/C stopped working. Around the same time, I thought I briefly heard something banging around behind the dash. Maybe unrelated.
Compressor wont come on.
Checked all fuses
Checked relay under hood
Swapped low pressure switch with a new one
Attempted to charge but would not take any freon.
Checked low side pressure. extremely high I assume since Compressor is not running.
Fan blows fine.
Heat is fine.
All cabin vents work as they should
All displays and controls operate normally.
Has climate control

Before I take this to a shop for a mega bill, is there anything else I can try. I assume there is no way to kick the compressor in to take a good reading on the pressure?

I have moderate mechanical knowledge and ability.

Thanks
Mark
 

kevinande

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You can bypass the low pressure switch to see if the compressor will run. Just use a paperclip or some small metallic object to complete the circuit. If it comes on shut it down immediately until you find the root cause. If it does not engage, I would look at the physical clutch. Make absolute sure it has refrigerant and it is filled to the proper level. If all fails it could be electrical or catastrophic physical compressor failure. We will hope it's not that serious.
 

wmwalton

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it is a 3 wire switch with a 5v signal line. it is my understanding that the sensor sends a variable voltage via this line to indicate pressure. Not like the old switches
 

m10ren

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New member here.
I have a 2012 Buick Lacrosse with the 4cyl E-Assist engine.
Last fall the A/C stopped working. Around the same time, I thought I briefly heard something banging around behind the dash. Maybe unrelated.
Compressor wont come on.
Checked all fuses
Checked relay under hood
Swapped low pressure switch with a new one
Attempted to charge but would not take any freon.
Checked low side pressure. extremely high I assume since Compressor is not running.
Fan blows fine.
Heat is fine.
All cabin vents work as they should
All displays and controls operate normally.
Has climate control

Before I take this to a shop for a mega bill, is there anything else I can try. I assume there is no way to kick the compressor in to take a good reading on the pressure?

I have moderate mechanical knowledge and ability.

Thanks
Mark
I am having similar problems, what was the problem and repair?
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Tmiller966

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Can someone one point me to location of the pressure sensor on the v6 2012 lacrosse? I can't find it anywhere and I am pretty good at this stuff.
 

rider47

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2010 LaCrosse with 3.0L V-6 VVT

I have seen info that says the base of the switch covers a shraider valve. The info said you can remove the pressure switch without
causing freon leak (assuming you want to test it or replace it).
 

Rich B.

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2016 LaCrosse & 2013 Boss 302 Mustang
2012 Buick LaCrosse with eAssist Gets 37 MPG on the Highway | The Torque Report These are well thought out ideas, nothing would be surprising.

I wonder, could it be a designed shutdown of A/C if driveability and or mileage or power train not up to expectations? Seems they have a shared charging system for cabin requirements and battery recharging. Who knows, answer may be yet found?

It figures, A/C on those was upgraded to electric driven from prototype belt drive? Understanding the 2012 Buick LaCrosse with eAssist System
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Last edited:

Dawg

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I have a 2012 touring. The air conditioning isn't working. It isn't low on refrigerant, the clutch relay is pulling in,changed the pressure switch,checked all the fuses and they are good. The clutch on the compressor isn't engaging. The fan is coming on and the control panel says the a/c is on and the temperature is set on lo. But still no air conditioning.
 

HotZ28

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Most common problem for the compressor not engaging with a full charge, would be the varible control valve in the compressor.
 

johnnyboys

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Where is the
varible control valve in the compressor
located and is there a way I can check if the compressor is working properly?
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singingotter

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I am having a similar problem with my 2012 Buick Lacrosse. The cabin air conditioning temperature started to fluctuate over a 15 minute period then quit. I can feel the a/c clutch relay pull in, but it will not engage. There appears to be plenty of a/c coolant in the system. I had to change the cabin filter, so while I was in there, I replaced the upper & lower temperature sensors. Still nothing.

I think today I will short the pressure sensor to see if that is the problem.

There are a lot of sensors on the climate control system these days: a/c coolant pressure switch, ambient temperature sensor, upper & lower cabin temperature sensors, solar sensor, a/c condenser fan running, and I'm sure the engine coolant temperature & others I've missed. I think there is also a climate control computer module that interfaces with the ECM. The Today's systems are sophisticated. The climate control computer module moves vent door servos to either cool or heat the cabin, and two different zones if you have that option (mine does). Lots of physically moving parts. Lots that can go wrong.

Sometimes the failure of a single component degrades system performance, other times the failure of a component is such the computer can't operate the system & will not engage the a/c compressor clutch. That's where I'm at.

It's a nice day outside, time to test the pressure switch.

Is there an easy way to test the clutch?

Has anyone come across a diagram of all of the sensors & switches that are a part of this particular models climate control system?

I have two ODBII analyzers, but it appears niether can access the climate control module.

I'll post my findings after testing the pressure switch.
 

HotZ28

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rider47

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Hi HotZ28,
The links are not created by me. They seem to be created by an automated process.
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G-516266

Any resolution on this? I am having A/C problem. Sometimes it works sometimes it doesn't. I replaced the cabin air filter. That wasn't the problem. I purchased a Cabin air temp. sensor and also A/C refrigerant temp. sensor. I haven't replaced them yet since I still haven't found where they are located.
 
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