BMW 116i 2005 air comes out only from defrost

[zeljko85]

Winter is really near and today was like 1 °C and air comes out only from defrost.


I have ihkr manual ac control panel ac panel.jpg Changing position with left knob doesn't do anything. Blower works just fine, i can set blower speed to any value but it blows hot just from deftrost. I can start AC, can hear that ac motor is engaged and can hear fan running. Air recirculation also doesn't work. Button emits green light but flap is not moving. Heated seats also doesn't work, but no light on them.
I have tried:

• checked all fuses,

• checked cables,

• run diagnostic scan with ista+ got codes (A6CF - AUC sensor, 9C48 - Mixing flap motor, 9C4A - Fresh/Recirculated air flap motor, 9C4D - Air distribution flap motor) (check attachment)

• removing errors doesn't help, they show up on next scan

• AUC sensor is nowhere to be found, or installation for it

Tried also to run module functions for ihkr and i get reading on position of mixing flap but it doesn't move. Also footwell temp/ventilation vent is a little bit off. (check attachment)


Ill try to remove servomotors and somehow test them, and try to test sensors if possible.


Can it be control panel is defected somehow (but like i said i can see when knobs are moving and its angle position)? Any ideas what to look, touch, punch to make it work?? Is it possible that wrong input data from sensors put ihkr to some kind of limp mode?

[MarcoZandrini]

The AUC senses air quality. Your car has the manual climate control module so there may no be an AUC in your car. The last code is the first priority as I believe that flap is what’s causing the “defrost only” air flow. How old is the battery? I ask as batteries tend to fail as the weather gets colder. These cars are rolling computers and whacky voltages cause whacky issues. Do you have a digital volt meter? You need to check the car’s voltage at idle and at 2000rpm. Please do so and report back.

[zeljko85]

I don't know how old battery really is, previous owner said he put new battery in August this year. I registered battery using ncsExpert hoped that will fix problem, but it didn't. Voltage before start 12.43V, idle 13.6V, 2000rpm 14.00V

[MarcoZandrini]

Those voltages are fine. I’m betting that the climate control module is acting up. Do you have a fuse panel layout card? Pull the fuses for climate control, wait 5 minutes and reinstall the fuses. Sometimes this will force these electronic modules to “reboot.” It takes a computer to really screw things up!

[zeljko85]

Done, pulled out all fuses that have something woth ac, blower ... nothing. Noticed that fsu have been changed and put valeo, can it be the culprit? Is module, control panel? Where is it hidden if not? How can i test servos? Pulled 2 out of 3, but i think that's not a problem, what are the chances that all 3 are dead. How can i test if they are getting any current?

[zeljko85]

Update - changed control panel, but nothing have happen. Do i have to somehow register new panel? Anybody know if i can delete auc sensor with ncsExpert since i don't have installation for it but it shows like an error in ista+ ?

[zeljko85]

Update
Things that i done:

• First tried to delete errors, with no success. Error just pop back,
• Control panel responded to ISTA functions (turn all lights, can read potentiometer angle, ...), checked that out
• flaps stuck at 255%
• Checked all fuses, all good,
• Battery was around 12.4V, so i checked that out
• According to newtis.info documentation flap motors are connected in line so if first motor fail rest wont work. So i put 2nd and 3rd in place of first flap motor. No good
• Checked all cables for open circuit or high resistance, all looks good
• Bought new fsu, no changes,
• Bought used klima control panel, no changes

I have run out of ideas what to look.

[Ojoya]

Hey did you figure out the issue?
I’m having the same issue only blows out of the defroster and no flaps responding on ihka module or on inpa flaps stay at 255. Got a used ihka module on eBay and nothing and switched the motor with another one and nothing...idk what else to do.