P1181

M4/3 (Engine/AC Electric Suction Fan)

Check Component M4/3 (Engine/AC Electric Suction Fan)

Test 1 Check Component M4/3 (Engine/AC Electric Suction Fan)
Test 2 Test Actuation of component M4/3 (Engine/AC Electric Suction Fan)
Test 3 Test PWM Signal for Operating the Suction Fan


1 Check Component M4/3 (Engine/AC Electric Suction Fan)

Test requirement
- CAN communication to control module N22 (AAC pushbutton control module) is o.k.

Test sequence
- Switch off ignition and then switch on.
- Operate engine at idling speed.

Status of the relevant actual values:
- Fan capacity request by air conditioning: Note! Communication with ECU required
- Fan capacity request by engine: Note! Communication with ECU required
- Temperature of coolant: Note! Communication with ECU required
- Air conditioning: Note! Communication with ECU required

Note: The electric suction fan for engine or air conditioning is off in the case of on/off ratio of 10%, and it runs at maximum speed in the case of an on/off ratio of 90%. When unplugging the socket of component B11/4 (Coolant temperature sensor), the fan capacity request (from engine) rises to > 90%.

Specified values
- Temperature of coolant < 80 °C, Air conditioning OFF : Suction fan STATIONARY
- Temperature of coolant < 80 °C, Air conditioning ON : Suction fan RUNNING
- Temperature of coolant > 95 °C, Air conditioning OFF : Suction fan RUNNING

Question
- Was the test o.k.?
Yes
The test was okay. ** End of Test **
No
The test was not okay.
Possible cause and remedy
- Test actuation of component M4/3 (engine/AC electric suction fan).

** End of Test **


2 Test Actuation of component M4/3 (Engine/AC Electric Suction Fan)

Note! Communication with ECU required


3 Test PWM Signal for Operating the Suction Fan

Test requirement
- CAN communication to control module N22 (AAC pushbutton control module) is o.k.
- Actuation is not okay.

Test sequence
- Switch off ignition.
- Connect socket box to component N3/10 (ME-SFI control module).
- (A.3) 3 <--> 6 (A.6)
- Operate engine at idling speed.

Status of the relevant actual values:
- Temperature of coolant: Note! Communication with ECU required
- Air conditioning: Note! Communication with ECU required

Specified values
- In the case of : Coolant temperature < 85 °C, Air conditioning ON: [2.5...12.5] V
- In the case of : Coolant temperature > 95 °C, Air conditioning OFF: [2.5...12.5] V

Question
- Are the measured values okay?
Yes
The measured values are o.k.
Further possible causes of fault
- Inspect cables from component N3/10 (ME-SFI control module) to component N65/2 (Suction fan control module).
- M4/3 (engine/AC electric suction fan)
- N65/2 (Suction fan control module)
No
The measured values are not o.k.
Possible cause and remedy
- Inspect cables from component N3/10 (ME-SFI control module) to component N65/2 (Suction fan control module).

** End of Test **