Climate control system improper operation with fault codes
B10A207, B105C07, B109F07 and/or B113600 in ACC control unit
Topic number

LI83.10-N-071291

Version

5

Function group

83.10 - Ventilation

Date

12/11/22

Validity

Model 907

Reason for change

Change to order of remedy and title

Complaint
Various customer concerns of Climate Control system operating inadequately.

Cause
Stepper motor linkage in the heater case may cause a mechanical fault during actuation during unfavorable environmental conditions.
NOTE: If the vehicle is equipped with H13 (rear additional heat exchanger), There is an additional stepper motor in
the rear heater case under the vehicle. This stepper motor can influence the normalization process.
May include fault code: B1A9C07 the output for control valve "Left water valve" has a malfunction. There is a mechanical fault.
The component is called N29/12 (rear additional heat exchanger ) .

Remedy
Remedy 1
1.Update software for N10 - SAM control unit and N22/1 - AAC control unit
Software levels:
•N10 (SAM): 907 902 44 04 or higher
•N22/1 (AAC): 907 902 45 04 or higher
2.Follow WIS to gain access to front ac stepper motors
a. Recirculation flap (AR83.10-D-2041TS)
b. Blend air flap (AR83.10-D-2026TS)
c. Distribution flap (AR83.10-D-2040TS)
11.12.2022 22:26:25
© Copyright Mercedes-Benz AG

JEFVNUK

Page 1 / 5

3.Remove all three front ac stepper motors. While removed, check linkage manually for proper movement (if concern
is related to temperature, please make sure temperature is achievable by manually moving the blend linkage)
4.Reinstall stepper motors (torque stepper motors to case at 1.8Nm)
*** Follow correct torque to prevent binding of stepper motors***
5.Connect XENTRY diagnosis and perform teach-in then normalization of stepper motors.
•If normalization is unsuccessful, continue to Remedy 2.

Remedy 2

1.In control unit view N22/1, actuate each stepper motors with Xentry actuation to locate actuator that is unresponsive
to input
•If all three front ac actuators are functioning, please check stepper motor in N29/12 (WIS doc. - Left water valve
(AR83.60-D-0003TSR))
2.Create TIPS case for further instruction. Please include findings from remedy 2 step 1.

Attachments
File

Description

remedy 2 motor location.jpg

Air recirculation flap actuator motor

remedy 2 motor removal.jpg

Air recirculation flap actuator motor removal

11.12.2022 22:26:25
© Copyright Mercedes-Benz AG

JEFVNUK

Page 2 / 5

remedy 2 linkage orientation.jpg

Linkage orientation

Rear additional heat exchanger.PNG

N29/12

H13 stepper motor1.PNG

Stepper motor in N29/12

11.12.2022 22:26:25
© Copyright Mercedes-Benz AG

JEFVNUK

Page 3 / 5

XPPI-stepper motor.PNG

XPPI- Stepper motor for N29/12 located with the other

WIS-References
Document number

Title

Note

AR83.10-D-2026TS

Remove/install blend air flap actuator
motor

AR83.10-D-2040TS

Remove/install air distribution flap actuator motor

AR83.10-D-2041TS

Remove/install fresh air/recirculated
air flap actuator motor

AR83.60-D-0003TSR

Remove/install regulation valve for
Stepper motor is connected to regulaheat exchanger of hot-water auxiliary tion valve but is available separately.
heater

Symptoms
Body > Air conditioning > Heater > Malfunction, air distribution

Control unit/fault code
Control unit

Fault text

N22/1 - Air conditioning (AAC) (HVAC177)

B1A9C07 - The output for control valve "Left water valve"
has a malfunction. ( Additional rear heat exchanger ) There is a mechanical fault.

11.12.2022 22:26:25
© Copyright Mercedes-Benz AG

JEFVNUK

Page 4 / 5

B105C07 - The actuator motor for the air recirculation
flap has a malfunction. There is a mechanical fault. (HVAC_F907)
B113600 - The measurement run for actuator motors for
air flaps has a malfunction. _ (HVAC_F907)
B10A207 - The actuator motor for the left blend air flap
has a malfunction. There is a mechanical fault. (HVAC_F907)
B109F07 - The actuator motor for air distribution flap "Defroster vent/center air vent/footwell vent" has a malfunction. There is a mechanical fault. (HVAC_F907)

Operation numbers/damage codes
Op. no.

Operation text

Time

540650

ON-BOARD POWER SUPPLY VOLTAGE MAINTAIN (WHEN CHECKING/
TESTING AND TROUBLESHOOTING)

0.1

541011

PERFORM QUICKTEST

0.2

833117

PERFROM NORMALIZATION OF AC- 0.2
TUATOR MOTORS ON HEATING/VENTILATION/AC HOUSING

833139

FRESH AIR/RECIRCULATED AIR
FLAP ACTUATOR MOTOR REMOVE AND REINSTALL WITH LINKAGE
CORRECTION

0.2

Only claim when performing remedy
2

833151

REPLACE AIR DISTRIBUTION FLAP
ACTUATOR

0.2

Only claim when performing remedy
2

833138

REPLACE ACTUATOR MOTOR OR
AIR MIXING FLAP

0.2

Only claim when performing remedy
2

11.12.2022 22:26:25
© Copyright Mercedes-Benz AG

JEFVNUK

Damage
code

Note

8046073

Page 5 / 5