Automatic Climate Control, ACC

B2410





Air recirculation motor. Short to B+
Air recirculation motor. Open circuit/short to ground

Fault symptoms
- The cabin mists up.
- Bad air in cabin.
- The perceived cabin temperature is too high compared to the set temperature.

Conditions
The following conditions apply:
- A short to B+ is indicated when the output for the air recirculation motor is not activated and the voltage on pin 21 exceeds 9 V.
- A short to ground and open circuit is indicated when the output for the air recirculation motor is not activated and the voltage on pin 21 is below 3 V.
- Measured every 440 ms and 5 consecutive measurements are required to set a diagnostic trouble code.
- The diagnostic trouble code is deleted after the ignition has been switched on 20 times if the fault conditions have not been fulfilled.
- When the diagnostic trouble code has been set the output is switched off.





Diagnostic procedure

1. Checking control voltage to motor
- Turn the ignition key to ON.





- Unplug the connector: Motor, air recirculation flap: (38).





- Connect a test lamp between pins 1 and 2 on the female connector.





- Turn the air recirculation on and off repeatedly.





- The red and green LED on the test lamp should go on alternately as air recirculation is turned on and off.

Is the function correct?
YES
- Replace Motor, air recirculation flap.
- Go to step 2.
NO
- Rectify defect lead.
- Go to step 2.





2. Final check
- Delete diagnostic trouble codes in all systems.





- Carry out a function check.
- Evaluate the function check.
- Check that the diagnostic trouble code does not recur.

Does the diagnostic trouble code recur?
YES
- See "Before changing a control module." Before Changing a Control Module

NO
- The steps taken to rectify the fault were correct.