AC/Heat Vent Flap Issue

shyne · 01-18-2023, 08:57 AM

Hello all! I just recently bought a 07 335i’ (01/07 build) so I figured I’d introduce myself here.

The car came with a couple of issues which I plan on tackling myself. I come from an E36 so I’d like to think I will be alright with this car

One of the issues I am trying to get out of the way is my ac vent flaps are not in working order.

I have pulled the following codes:
9C48: Mixed air flap left (LIN)
9C49: Mixed air flap on the right (LIN)
9C4A: Fresh air / circulating air / dynamic pressure flap (LIN) 9C4B: Defrost flap (LIN)
9C4C: Footwell flap (LIN)
9C4E: Layering flap (LIN)
9C50: Rear ventilation flap (LIN)
9C52: Ventilation flap (LIN)

I have done a bit of research and found a couple of other posts with similar issues being solved by reseating the IHKA connectors. Tried that myself but no luck.

I tried to get ISTA working to look at the connections that could possibly be causing issues, but no luck there either. To my understanding these motors are wired in series so an unplugged connector is sure to cause all the motors to not work.

When the connectors seat to the climate control I hear movement but I am still getting all those errors and unable to change the vent flaps position.

Any advice or suggestions would be greatly appreciated! Thank you in advance

shyne · 01-21-2023, 12:18 PM

I went ahead and took my glovebox out hoping to find a loose connector and finally solve my problem.. But, all my connections are fine nothing seems wrong. I wanted to test if power was getting to the motor to begin with so I did more research.

Still unable to get ISTA working and newtis links are all not working so I'm left with scraps and rewording my searches for hours.

I was able to find a diagram that seems to match my wiring.

Link to thread:
https://www.e90post.com/forums/showthread.php?t=1689523

I didn't want to revive a old thread but it did line up with my situation til the end.

I used a multimeter to check for continuity between connectors X01198 and X4706 on the yellow LIN_BUS wire. It didn't read any resistance between my wires. I'm stumped. Checking for voltage between my red (pin 4) and brown (pin 1) and it was reading 11.9. Pretty normal.. maybe?

So I now know there is an issue with my LIN_BUS wire but I am unable to find any breaks. Any suggestions??

01-18-2023, 08:57 AM	#1
shyne New Member 22 Rep 25 Posts Drives: 07' E92 335i Join Date: Jan 2023 Location: Northern Virginia iTrader: (0) Garage List 2007 BMW 335i [0.00]	AC/Heat Vent Flap Issue Hello all! I just recently bought a 07 335i’ (01/07 build) so I figured I’d introduce myself here. The car came with a couple of issues which I plan on tackling myself. I come from an E36 so I’d like to think I will be alright with this car One of the issues I am trying to get out of the way is my ac vent flaps are not in working order. I have pulled the following codes: 9C48: Mixed air flap left (LIN) 9C49: Mixed air flap on the right (LIN) 9C4A: Fresh air / circulating air / dynamic pressure flap (LIN) 9C4B: Defrost flap (LIN) 9C4C: Footwell flap (LIN) 9C4E: Layering flap (LIN) 9C50: Rear ventilation flap (LIN) 9C52: Ventilation flap (LIN) I have done a bit of research and found a couple of other posts with similar issues being solved by reseating the IHKA connectors. Tried that myself but no luck. I tried to get ISTA working to look at the connections that could possibly be causing issues, but no luck there either. To my understanding these motors are wired in series so an unplugged connector is sure to cause all the motors to not work. When the connectors seat to the climate control I hear movement but I am still getting all those errors and unable to change the vent flaps position. Any advice or suggestions would be greatly appreciated! Thank you in advance
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01-21-2023, 12:18 PM	#2
shyne New Member 22 Rep 25 Posts Drives: 07' E92 335i Join Date: Jan 2023 Location: Northern Virginia iTrader: (0) Garage List 2007 BMW 335i [0.00]	I went ahead and took my glovebox out hoping to find a loose connector and finally solve my problem.. But, all my connections are fine nothing seems wrong. I wanted to test if power was getting to the motor to begin with so I did more research. Still unable to get ISTA working and newtis links are all not working so I'm left with scraps and rewording my searches for hours. I was able to find a diagram that seems to match my wiring. Link to thread: https://www.e90post.com/forums/showthread.php?t=1689523 I didn't want to revive a old thread but it did line up with my situation til the end. I used a multimeter to check for continuity between connectors X01198 and X4706 on the yellow LIN_BUS wire. It didn't read any resistance between my wires. I'm stumped. Checking for voltage between my red (pin 4) and brown (pin 1) and it was reading 11.9. Pretty normal.. maybe? So I now know there is an issue with my LIN_BUS wire but I am unable to find any breaks. Any suggestions??
	Appreciate 0 Quote