Coolant Fans -V7- and -V177-, Checking
Coolant Fans -V7- and -V177-, checking
Special tools and equipment
^ V.A.G 1526 A
^ V.A.G 1594 A
^ V.A.G 1598/31
^ VAS 5051 with VAS 5051/1
Test sequence
- Connect vehicle diagnostic, test and information system VAS 5051 and select vehicle system "01 - Engine electronics". When doing this ignition must be on.
Display on VAS 5051
- Select diagnosis function "03 - Final control diagnosis" from menu -1-
- Press the (arrow) button repeatedly until following display appears:
Display on VAS 5051:
A - Actuator test is waiting Continued switching required
11 - Radiator fan control 2
- Press the (arrow) button.
Display on VAS 5051:
A - Actuator is running - Continued switching allowed
^ Coolant Fan Control (FC) Control Module J293- (on fan motor) slowly switches Coolant Fan -V7- once to full speed, unless diagnosis is advanced to next final control element by pressing the (arrow) button.
- Press the (arrow) button.
Display on VAS 5051:
A - Actuator test is waiting - Continued switching required
12 - Radiator fan control 1
- Press the I* button.
Display on VAS 5051:
A - Actuator is running - Continued switching allowed
^ Coolant Fan Control (FC) Control Module 2 -J671 - (on front left longitudinal member) slowly switches Coolant Fan 2 -V177- once to full speed, unless diagnosis is advanced to final next control element by pressing the (arrow) button.
- Press the (arrow) button to exit from function "03 - Final control diagnosis".
If fan activation does not react as described:
- Create prerequisites for start-up of radiator fans on basis of criteria mentioned previously (e.g. switching on air conditioning system, increasing engine temperature accordingly).
Display on VAS 5051:
- Select diagnosis function "08 - Read data block" from menu -1-.
Display on VAS 5051:
1 - Enter display group
- Using keypad -2-, enter "135" to select "Display group 135" and confirm entry with Q button.
- Check display in display zones -2- and -3-.
If on-off ratio does not rise above 10%:
- Interrogate fault memory of engine control unit.
- Eliminate displayed faults if necessary.
If respective fan does not start up although on-off period is above 10%:
- Test Coolant Fan -V7- go to Page 19-86 or Coolant Fan 2 -V1 77.