03 e53 AC problems
 

Sunroof was left open in rain storm. AC was working but honestly cant say how recently as I don't drive the vehicle, my wife does and she rarely uses it, but we are approaching 100 degrees here and I need it now.
Tests so far:
Temp control all seems normal, light comes on for AC button.
Compressor clutch does not engage.
Auxillary fan does no activate.
INPA will not connect to module, but on general info screen shows AC is not on and clutch not activated.
Attachment 84985
No voltage at compressor clutch
injecting 12v does activate clutch and cool.
Pulling the pressure sensor on the AC high line does not activate the Auxiliary fan.
Reseated plugs on thermostat inside cabin

Anything else to try before replacing the thermostat control?
Salvage yard is 3 hr round trip and since this has the rotary style controls, I'm very limited on what years of the X5 work, and the lots only shows 1. No idea if the part is even there.

Welcome to the site.

Are the fuses in glove box good? Grab the module for manual temps. Does heat and internal fan work?

Fuses good.
Heat works. Fans work.
Hoping to find the module. What other years would have the manual temp version? Very little in yards around me.

In '03, auto temp units were available. I assume 99-03 have a manual option.
The part number is 64116916654
Air Conditioning Control.
REALOEM also list the parts -> X5 E53 (08/1999 — 09/2006)

Where was the aux fan fuse located that you checked? There is a batch of 2003 model years that had this fuse moved to where it is on the 2004+ models, but the wiring diagrams produced by BMW showed it in the old location. This had me chasing my tail for a long time. I know there's been at least one other 2003 owner who found this to be true.



Post 9-10 is where the info is: https://xoutpost.com/bmw-sav-forums/...continues.html

Following the link I just puled the whole fusebox down, and the fusible links are good also.
Using INPA, I could activate the compressor and get cold air. In fact, with it activated, the switch on the control panel worked to enable and disable the compressor as it should.
I was trying to find a way in INPA to look at the auxiliary fan but didn't see anything.
The fan does not start at all, even with the AC pressure sensor disconnected and I thought it was supposed to go into failsafe and run 100%.
If I understand correctly, if the system cannot see that fan engage, it will not engage the compressor. IS that correct?
When I 1st bought the car a year ago, the fan ran constantly even with the key off. I replaced it with a salvage one and the problem went away. But I'm wondering if the replacement has failed completely, locking out the AC.

Fan running constantly is a sure indication of a problem.

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That was a year ago before I replaced the fan. It has operated correctly since then until now.

Aux fan is controlled by engine ECU (DME). AC module (IHK) commands the fan via DME. So possible fault code and activation is found in DME.

When I had AC problems a few years ago on my 2002 X5 with the M54 engine, the compressor would not engage at all when the aux fan failed. New auxiliary fan fixed the problem for me. Job's a bit of a hassle though.

Chris
Lockhart, Texas

Only error codes in DME are 202 and 203 lambda codes.

Can't remember the code that came up when I contended with the fan not responding...but I do remember when I cleared the code along with installing a compatible fan from Amazon...the M54 was back in business. I haven't looked back since and that was 7 to 8 years ago .

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using inpa, i was able to activate the fam and it worked.
I tried the temperature display cluster adjust function and it did not activate the compressor clutch. IS there a way to read the freon pressure?

Put a set of gauges on, should have been the first thing and has been said many times on this forum.

activated clutch in inpa, then unplugged the pressure sending unit and clutch stopped, plugged back in and it runs, so I'm confident it is good. It's just as if the cars is never demanding AC. So I'm really leaning towards the control module/panel.

Sorry, thought that was in the original post but it was not. Yes, did start with gauges on the freon and of course high and low side are the same but very close to 40.

Should also add, just replaced the manual control with no improvement.

Can a faulty hedgehog screw with the compressor? I know it screws the blower motor, not sure about the compressor....

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What are pressures when the clutch is active? Low side should be between ~35-40 and 150+ PSI on the high side.

Both sides at 40 PSI means the refrigerant is pretty much empty, or it's cold outside ;)

Empty! Tighten up the valve cores. Put a vacuum on it. Charge it up!

I'll check that when she gets back home later today. I wasn't using INPA to activate the clutch when checking so I only had a static pressure.

checked pressures just now. 88 ambient temp. 82psi on high and low. Activating the compressor does not change at all. Normally I would go with bad compressor, but the system is not activating without inpa either, so I wonder if I have 2 problems at the same time. But manually activating it should have pulled the low and raised the high even if everything else is out of the picture.

Make sure your gauges are properly attached and reading correctly. What happened to the 40 PSI ??

I must have been wrong. I was going from memory and admittedly I have memory problems, so I started fresh and took photos this time.
Gauges have worked fine on other vehicles. I even burped both lines and only opened them one at a time to make sure I was not cross reading.

I have completely rebuilt AC systems on my other vehicles, so I have some experience.

What were the gauges reading before you turned the valves down ?? It sounds to me an awful like you are not reading the actual pressure in the lines and the system is actually too low to let the compressor activate.

Zero.

then after opening the low side and the low gauge went to 83, I vented it back down to zero and did the same to the high. Then treated them like normal and opened the quick disconnects and read both sides at the same time. Then used INPA to activate the compressor with no change to high or low. No bottle attached at the time.
I do appreciate the help, but I have been working on AC units in cars for 30+ years. Just not the BMW systems. Normally I would have just jumped the pressure switch and looked at my levels.

Then you are right and you have 2 or more problems, one of them likely a compressor stuck on zero volume which some people have been able to unstick, at least temporarily, by revving the engine.

And any clue on the non engagement of the compressor?

As already suggested, aux fan not working could be another issue.

I could believe that but I can activate the fan with INPA

I'm not familiar with the non IHKA (auto temp) set up, but it sounds like it's not seeing or liking something. If you can work all the outputs through IMPA but still have no air there must be an input missing.

You could try pulling the lower rad hose temp sensor and see if the DME turns on the aux fan just to see if it has some control of it.

You could also try defrost to see if that kicks the compressor in.

I'll try the temp sensor. Did already try defrost. Too hot today to even try

Auxiliary fan does not engage with lower hose temp sensor unplugged, but does when activated in INPA and is speed controllable there.

Well that is interesting. I'm thinking the aux fan maybe doesn't pass the test for the DME but doesn't need to if it gets activated through INPA. Can you read the evap temp in INPA?

Don't remember seeing that in INPA, but I cant get into the AC module at all. I kinda assumed it was since I have manual controls

Hopefully someone who knows something about the manual controls will chime in. You should probably get a wiring diagram and theory of operation for the manual controls. It still could be the aux fan but that will be hard to eliminate without having a known good one to plug in.

I see in your first post INPA is showing the A/C input and compressor, that is from the DME then ? Is there even an A/C module ? I know the Evap temp sensor is different for the manual controls so maybe there is not even an A/C module ??

I think I'll chase the aux fan issue. It's apparently not right anyway and it may be the key to half of this problem. I'll start a fresh thread with details.

When you say there is no voltage at the compressor clutch, have you measured or are you assuming there is no voltage because the clutch doesn't cut in ? Have you tried revving the engine to get the compressor compressing ?

I measured it. Pierced the wire and took voltage. It does come up when the INPA turns it on, but not when I request it from the temp selector.
Yes, I did rev the engine to near redline with INPA turning on the compressor, and still no delta on the gauges. Tried without INPA just to cover all options and it still not not engage or change pressure.

Just wanted to update. Replaced auxiliary fan with new. No change.

Pretty Crazy! New OE ? Does INPA show the request for A/C from the button ?

Clutch control sequences. I'll would take a look at wiring.

Is there a rear fan installed?

New aftermarket. INPA does NOT show the request.

Do you mean inside the cabin? Not that I'm aware of.

I would concentrate on figuring out why the DME doesn't see the A/C button, or even defrost button?? It still would be nice to know if there is a controller involved with the manual A/C and how it is wired, and if there is a bus involved, any chance you can get a hold of that info ??

What module are you reading to get evap temp etc. ?

So I had a look in the Bentley manual and it's all there! ;) The IHKR(manual control) is a module itself just like the IHKA. BOTH operate the compressor clutch directly so you probably are operating the compressor and monitoring functions with INPA through the IHKR not the DME. You really really should have a Bentley manual!

Do rear vents have a speed dial? If so, it has a fan in the console. Your model shows it's an option.

It looks like the the DME can "signal" the IHKR to turn off the compressor so would be really good to know what module you are in when turning the compressor on. There could be something going on with the connection from the DME to the IHKR or maybe even a "data bus" issue which might be explained by rain into the open sunroof.

howdoes the Aux fan tie-into the IHKR
 

Added photos:
Attachment 85065 HVAC controls, rear of console

Attachment 85066 IHKR, Northern Hemispere version, I presume

Question: Comparing the IHKR to the IHKA in the Bentley manual, I don't see where the Aux fan is represented in the input/output chart shown, but it is clearly shown in the IHKA chart. Am I missing something?

The aux fan is an output for the DME.

The compressor on/off wire going to the IHKR from the DME might be something to look at. Some more reading about how it works (is there anything bus controlled on the IHKR??) and knowing what modules are being read and activated would help.

https://www.instagram.com/reel/DN7BI...5paHdoN2l3OTcz

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how is replacing the schrader valves going to help me?

It's not your issue, but since you're working on your system, doing additional preventive maintenance is a good/common thing...

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A $3 part is very common for A/C failures. I've saved probably 70% of non working A/C systems by replacing core valves. Even when shops have recommended compressor replacements. If a vacuum holds -28 Hg, the leak location is probably a valve core. Some OE designs have only one seal. Replacement cores can have two seals. As a test, use a tool to tighten the cores. If the tool turns even a fraction, the leak location is likely there. If I vacuum a system, I change the cores. I've fully charged systems only to have a core leak. It's good preventative maintenance to change out cores.

If diagnosing isn't your strong point and you want to use the parts cannon then replacing the dash control (IHKR) might be a good guess especially if you can get one for cheap at a wrecker. If you get lucky you might even find a good compressor, maybe one that has been replaced.

I think the manual air might not use the variable displacement compressor so something else to check into as well.

Hey X5chemist - I'm curious which brand of cores you use and/or recommend. I've never been able to discern which newer replacements have two seals. I generally stick with OEM, but BMW OEM cores look like they still have just the one o-ring (if product photos can be trusted, anyway).

Best regards,
Chris

2005 X5 30. Schwarz Black
2002 X5 3.0 Titansilber

Mine has Santech 64536922944 cores. It's a two seal type. One seal is where it touches the port. The other seals the bottom where refrigerant enters. Rub A/C oil on the seal when replacing them. I think the OEM seals are dual seal types. Single type seals are 90's and older types. More like, they do have two seals. The second seal is inside the core. Newer styles have a visible seal mostly at the lower core portion. Cores are much larger too.