Clicking noise when I start may car
Just for the fun of it, I tried to reset the temp control unit by pressing and holding both RECIRC and DEFROG buttons together. The indicator lights blinked and they would not stop, also, the clicking noise started and would not stop this time. I had to get off the road and restarted the car.
Other than the clicking noise when I start the car, everything seems OK. Before I bring in my car to scan the code, any idea to what went wrong?
He said the problem would be the stepper motor (servo), the linkage cracked and hence the noise. The noise appears during HVAC self test when the car is started. He was actually quite sure of this.
I checked the price of this stepper motor: MB parts: $105US, Aftermarket: Behr: $58US.
Does one stepper motor control both sides or there are two?
Last edited by mis3; Jun 17, 2015 at 02:17 PM.
These levers (flaps) were changed 4-5 years ago. At that time, the air on the driver side would come out only in the foot area. There was no clicking sound at that time. I remember I did reset the system (RECIRC and DEFROST) and the blinking would stop in 30 seconds.
This time, there is clicking noise and upon reset, the blinking would not stop.
Last edited by mis3; Jun 17, 2015 at 04:13 PM.
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By linkage, do you mean the linkage kit (2038300032) or the lever kit (2038300033)?
Also, is there one or two servo motors behind the center console?
Last edited by mis3; Jun 19, 2015 at 11:02 AM.
A2038201642 is the "stepper motor" or servo that drive the linkage that operates the flap. If you have the "full dual" climate control where both sides can set separate vent outputs (not just separate temps), then have 10 of these servos and ten linkages and ten flaps. If you have the standard climate control with separate temp controls but shared vent control, then you have six of them.
When you have a problem, it's best to get a scan of the ACC to know which one(s) are causing the problem. They all share the same servo and linkage, but there are different "flaps" or "levers".
I asked maybe the stepper motor failed and he said that the clicking noise was the motor trying to turn the lever. According to them, this showed that the motor was working.
I will report back after the activity.
Last edited by mis3; Jun 23, 2015 at 03:09 PM.


