Ventilation Fan Not Functioning

Ventilation Fan Not Functioning

Fault symptoms
No ventilation fan

Diagnostic help
Do not use thin jumper leads as the fan operates with high current.

The fan commutator must not be lubricated at all.

There is a risk of short-circuiting the poles.





Diagnostic procedure

1. Check the fuses
^ Check fuse 22.

Is the function correct?
YES
^ Go to step 2.
NO
^ Replace: Fuse 22.
^ Go to step 8.





2. Checking the fan's power supply
^ Unplug connector: H2-2.





^ Connect a test lamp between pin 1 on the female connector and a reliable grounding point.





^ The test lamp should light.

Is the function correct?
YES
^ Go to step 3.
NO
^ Rectify lead in question.
^ Go to step 8.





3. Checking the fan's ground connection
^ Connect a test lamp between pins 1 and 2 on the female connector.





^ The test lamp should light.

Is the function correct?
YES
^ Go to step 4.
NO
^ Rectify lead in question.
^ Go to step 8.





4. Checking the fan motor
^ Connect a jumper lead between pin 2 on H2-2 and pin 1 on the ventilation fan (red/brown lead). Important! Use lead with x-section area 6 mm for the jumper, otherwise there is a risk that the lead will melt.





^ The fan should start and operate at full speed.

Is the function correct?
YES
^ Go to step 5.
NO
^ Replace : Motor, ventilation fan.
^ Go to step 8.





5. Checking the power supply to the ventilation fan control
^ Unplug connector: Ventilation fan control : (220)





^ Connect a test lamp between pin 3 and a reliable ground.





^ The test lamp should light.

Is the function correct?
YES
^ Go to step 6.
NO
^ Rectify lead in question.
^ Go to step 8.





6. Checking reference ground lead, ventilation fan control
^ Connect a jumper lead between pins 35 and 1. Note that the jumper lead is connected on the back of the connector without removing the connector from the ACC panel





^ Connect a test lamp between pins 2 and 3 on the female connector





^ The test lamp should light.

Is the function correct?
YES
^ Go to step 7.
NO
^ Rectify lead in question.
^ Go to step 8.

7. Checking the wiring
^ Check the wiring to the ACC control module connector.

Is the wiring intact?
YES
^ See "Electronic Climate Control, Testing and Inspection." for DTC B2425 (ACC). Testing and Inspection

NO
^ Rectify lead in question.
^ Go to step 8.





8. Final check
^ Delete diagnostic trouble codes in all systems.
^ Carry out a function check.

Is the function correct?
YES
^ The steps taken to rectify the fault were correct.
NO
^ Before Changing a Control Module