Group 87 Climate Control, Fault Codes
Troubleshooting
8730-21-02-04
MID 146 SID 9 Stepper Motor, Air Mix/Heat Control, Check
Special tools: 9990025, 9998699
Other special equipment: J-39200
NOTE
•
Check all relevant connectors. Check for loose
connections, contact resistance and oxidation. For a
more detailed description of fault-tracing cables and
connectors, see service information group 371.
Measurement at the component
connector to the control unit
Note: If one of the values below is incorrect this may also
have caused the component to fail, check the component
if any of the values are incorrect.
Signal cable
1
Conditions:
•
Control unit connected.
•
Measuring voltage using the J-39200 Digital
Multimeter.
•
Ignition key in the drive position.
•
Measurement to the control unit.
•
Control unit connected.
•
Stepper motor active.
Measurement points
Nominal value
BSB11 - BSB7
V
≈
< 10 V
BSB11 - BSB8
V
≈
< 10 V
BSB11 - BSB9
V
≈
< 10 V
BSB11 - BSB10
V
≈
< 10 V
Note: If the measurement value exceeds 10V there is
probably an open circuit in the cable to the stepper motor.
J-39200
9990025
, 9998699
19
