[adhil@KL]

My bmw E90 2011 have this complaint with air condition, I’ve been trying to fix for months and still,
The complaint is that the air conditioner cools but doesn’t last long it just turns off randomly also if I off the ac with the button and turn it on again it most of the time doesn’t turn on,
I checked for leak found non, I also checked the fuse it also good , I checked the temperature sensor under the bumper and it’s working fine , the compressor is working and probably checked most of thing , recently I checked with a scanner and found fault code on AUC sensor which I don’t know how to check it ,

[BRG_N54]

System is probably low on refrigerant. I just did my '07, it had 6 oz of refrigerant left in it. Leak tested OK, but well shy of the 20 oz it should have after 16 years.

[mainbearing]

Yes probably just low refrigerant. You need to check the pressures when it is working and when it is not. I would let a shop do it for refrigerant safety.

If your scanner can display the evaporator temperature as well as the high pressure those info will be useful.

[gbalthrop]

Originally Posted by adhil@KL

... E90 2011... the air conditioner cools but doesn’t last long it just turns off randomly also if I off the ac with the button and turn it on again it most of the time doesn’t turn on... the compressor is working... found fault code on AUC sensor which I don’t know how to check it ...

A6CF or other JBE Fault Code related to AUC Sensor will NOT prevent compressor operation. When you say: "it just turns off randomly", WHAT is turning off? Compressor Valve Green LED? Entire IHKA Control Panel? Blower?

If the Compressor Valve is "turning OFF" randomly, causes for THAT include:
1) Low Refrigerant Pressure (Actual);
2) BOGUS Low Refrigerant Pressure Signal from Pressure Sensor located near the Washer Filler Tube on vehicle right of engine;
3) Compressor Valve Wiring;
4) Other wiring or IHKA Module Fault.

A knowledgeable Refrigeration (A/C) shop should be able to diagnose the issue. Manifold Gauges connected to the Refrigerant Ports (High Side & Low Side) will show an experienced "Tech" what is happening (pressures related to Ambient Temp).

The E90 Climate Control System has sensors that can show:
1) Refrigerant Pressure, High Side, between Condenser & Evaporator;
2) Evaporator (cooling coil) Temperature;
3) Flap positions (how much of cooled air is directed through heater core);
4) Other Temperature data & status of compressor Valve.

INPA (BMW Factory-Level Diagnostic Software) ScreenPrints are found in the attached IHKA Tutorial pdf. That Tutorial shows example INPA Screens, & explains HOW the Climate Control system (IHKA 87) on my 3/2007 328xi works. When you post back, please provide Last-7 Characters of VIN.
George

[adhil@KL]

Originally Posted by BRG_N54

System is probably low on refrigerant. I just did my '07, it had 6 oz of refrigerant left in it. Leak tested OK, but well shy of the 20 oz it should have after 16 years.

I recently got it checked by a local mechanic and he filled the refrigerant and also the condenser inside the dashboard had an complaint , so also got it replaced
It’s been 1-2 months since, so I’ll check it again I don’t know if there’s an leak in the system

[adhil@KL]

Originally Posted by mainbearing

Yes probably just low refrigerant. You need to check the pressures when it is working and when it is not. I would let a shop do it for refrigerant safety.

Originally Posted by mainbearing

If your scanner can display the evaporator temperature as well as the high pressure those info will be useful.

I recently got it checked by a local mechanic and he filled the refrigerant and also the condenser inside the dashboard had an complaint , so also got it replaced
It’s been 1-2 months since, so I’ll check it again I don’t know if there’s an leak in the system

[adhil@KL]

Originally Posted by gbalthrop

A6CF or other JBE Fault Code related to AUC Sensor will NOT prevent compressor operation. When you say: "it just turns off randomly", WHAT is turning off? Compressor Valve Green LED? Entire IHKA Control Panel? Blower?

If the Compressor Valve is "turning OFF" randomly, causes for THAT include:
1) Low Refrigerant Pressure (Actual);
2) BOGUS Low Refrigerant Pressure Signal from Pressure Sensor located near the Washer Filler Tube on vehicle right of engine;
3) Compressor Valve Wiring;
4) Other wiring or IHKA Module Fault.

A knowledgeable Refrigeration (A/C) shop should be able to diagnose the issue. Manifold Gauges connected to the Refrigerant Ports (High Side & Low Side) will show an experienced "Tech" what is happening (pressures related to Ambient Temp).

The E90 Climate Control System has sensors that can show:
1) Refrigerant Pressure, High Side, between Condenser & Evaporator;
2) Evaporator (cooling coil) Temperature;
3) Flap positions (how much of cooled air is directed through heater core);
4) Other Temperature data & status of compressor Valve.

INPA (BMW Factory-Level Diagnostic Software) ScreenPrints are found in the attached IHKA Tutorial pdf. That Tutorial shows example INPA Screens, & explains HOW the Climate Control system (IHKA 87) on my 3/2007 328xi works. When you post back, please provide Last-7 Characters of VIN.
George

When is say it turn of the coldness of the air goes down , the blower work good.
I can see this while observing the engine fan , it turn off when the coldness turns off , and it turn on the coldness is restored , but while cars running, if I ever turn off the ac with the green button on the dash then if I turn it back nothing happens no cold just air coming out..
I have replaced the CONDENSER of the car by a local mech and that’s when this rendom turning off start to happen , someday the air coming out will be very hot
also there’s leak in my exhaust system near engine , and I can get the odour into my cars cabin , can this cause the AUC sensor to do something which effect the coldness ,
AUC sensor complain is the only complaint when reading through the scanner

CD (Control Display - CIC/CCC-BO/CHAMP-BO/ M-ASK-BO/RAD/RAD2-BO)1 Problems exist
1, A6CF JBE: AUC Sensor
This 👆🏻 is the fault code , I don’t understand it ,

[mainbearing]

The AUC sensor is the air pollution sensor. I should not affect the AC I do not think. Not sure.

I thought E90s have variable displacement compressors, therefore no clutches. The pulley should rotate at all times, unless in your area BMW put clutches on there.

If variable displacement, I wonder if the shear blocks in the pulley sheared off, and that the pulley was just catching and uncatching, giving you cold air and sometimes no cold air.

[lowrydr310]

I have a similar issue with my 335 AC not working well. It used to cycle off and on frequently. I took it to a BMW independent shop who evacuated the system and recharged with the proper mass of refrigerant. It's better, but still not blowing ice cold and still occasionally cycles off. What next? All the flaps seem to be functional according to the data from within INPA. Evaporator temperature isn't nearly as cool as my 330, hovering around 14C but will eventually get to 12C. My 330 quickly gets to 10C.

[adhil@KL]

Originally Posted by mainbearing

The AUC sensor is the air pollution sensor. I should not affect the AC I do not think. Not sure.

I thought E90s have variable displacement compressors, therefore no clutches. The pulley should rotate at all times, unless in your area BMW put clutches on there.

If variable displacement, I wonder if the shear blocks in the pulley sheared off, and that the pulley was just catching and uncatching, giving you cold air and sometimes no cold air.

It has an compressor clutch and I got it checked by a mech and it okay he said,
When the ac cuts off I can only observe the engine fan goes off and nothing else

[adhil@KL]

Originally Posted by gbalthrop

A6CF or other JBE Fault Code related to AUC Sensor will NOT prevent compressor operation. When you say: "it just turns off randomly", WHAT is turning off? Compressor Valve Green LED? Entire IHKA Control Panel? Blower?

If the Compressor Valve is "turning OFF" randomly, causes for THAT include:
1) Low Refrigerant Pressure (Actual);
2) BOGUS Low Refrigerant Pressure Signal from Pressure Sensor located near the Washer Filler Tube on vehicle right of engine;
3) Compressor Valve Wiring;
4) Other wiring or IHKA Module Fault.

A knowledgeable Refrigeration (A/C) shop should be able to diagnose the issue. Manifold Gauges connected to the Refrigerant Ports (High Side & Low Side) will show an experienced "Tech" what is happening (pressures related to Ambient Temp).

The E90 Climate Control System has sensors that can show:
1) Refrigerant Pressure, High Side, between Condenser & Evaporator;
2) Evaporator (cooling coil) Temperature;
3) Flap positions (how much of cooled air is directed through heater core);
4) Other Temperature data & status of compressor Valve.

INPA (BMW Factory-Level Diagnostic Software) ScreenPrints are found in the attached IHKA Tutorial pdf. That Tutorial shows example INPA Screens, & explains HOW the Climate Control system (IHKA 87) on my 3/2007 328xi works. When you post back, please provide Last-7 Characters of VIN.
George

Here’s the last seven numbers of vin :
9086763

[ptpending]

Originally Posted by adhil@KL

Here’s the last seven numbers of vin :
9086763

you need to provide not only number but letters
so this should be last 7 symbols of the VIN
the second thing is that if nobody services the air conditioning before, that the compressor may run without oil and already damaged
the aircon system should be checked and/or serviced in the beginning of the every hot period, to see what is the current performance of the AC
i do know that kerala is hot place...

[Hoody007]

Just to make sure: has your evaporator or condenser been replaced? The evaporator is in the dash, condenser near the radiator.

How old is your battery? Any low voltage codes? Might be turning off the compressor under load…

[adhil@KL]

Originally Posted by Hoody007

Just to make sure: has your evaporator or condenser been replaced? The evaporator is in the dash, condenser near the radiator.

How old is your battery? Any low voltage codes? Might be turning off the compressor under load…

I’m not sure if it’s condenser or evaporator, but I’m sure it’s from the dashboard so it’s probably the evaporator,
I had an connection issue with my battery before, but now it’s fine and the battery is 2years old
No I don’t see any low voltage codes , the only codes I have is :
1. FRM footwell module (power window and light related)
2. AUC sensor (air quality related)
3. The central display (display is red when turning on ,and goes black after sometime)

[marvinstockman]

Does you fan stop working, or do you lose airflow but hear the fan. Or does the fan stay on and just blows warm air.

Theirs a different solution for each problem.

[adhil@KL]

Originally Posted by marvinstockman

Does you fan stop working, or do you lose airflow but hear the fan. Or does the fan stay on and just blows warm air.

Theirs a different solution for each problem.

The engine fan turns off, when this happens
The fan in the cabin works and blows warm air

[adhil@KL]

An quick Update, I checked The plug of the engine fan and found that the positive pin
of the fans plug is not have power, but the negative and the signal pins Have power, this must be the case when the AC does not turn on, but when the AC turn on, probably the fans positive plug has power
I also checked the continuity of the positive pin of the fans plug to the positive terminal(jumper on the front) and those does not have continuity
The negative has continuity
So this feels like an chip level/electric /software, issue and also is this related to the ECM and other signal related

• The wiring I haven’t checked but,
• the fuses and relay at the glove box I have checked and it’s good ,
• Now I did a quick Internet homework and found that there’s an temperature sensor which send signal into ECM so I have to check it ,

After all this I may have to check the ECM and maybe reprogram it ,