Checking Coolant Fan -V7- (Left)

Checking coolant fan -V7- (left)

Test requirements:





^ Fuse S42 for radiator fan OK (in 8-position relay carrier, position 19)
^ Fuse S146 for radiator fan OK (in 8-position relay carrier, position 21)





- Disconnect connector (arrow).








- Connect multimeter for voltage measurement as follows.
^ Specification: approximately battery voltage
If readings do not match specifications:
- Use wiring diagram to eliminate open circuit in wiring.
If readings match specifications:





- Connect multimeter for voltage measurement as follows.
^ Specification: approximately battery voltage
If reading does not match specification:
- Use wiring diagram to eliminate open circuit in wiring.

If reading matches specification:





- Connect multimeter for voltage measurement between contacts 3 and 4.
^ Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01- Engine electronics" selected. Ignition must be on.





Indicated on VAS 5051:
- From list -1- select diagnostic function "03- Final control diagnosis".
- Keep touching > until the radiator exhaust control 1 is activated.
^ Voltage value must slowly drop from approximately battery voltage to roughly 8 V (and then increase again)
- Terminate function "03- Final control diagnosis" by touching < key.
- Switch ignition off.
If the specified value is not reached:





- Connect test box VAG 1598/31 to wiring harness connectors. Engine control module is not to be connected. Connect ground clip of test box to ground (not shown in Fig.).

CAUTION: So as not to destroy electronic components, select required measuring range before connecting test leads and observe test conditions.








- Check for open circuit and short to ground/positive in the following wiring.
- Use wiring diagram to eliminate open circuit in wiring/short circuit.
If no fault is found:
- Replace coolant fan -V7- with coolant fan control (FC) control module J293-.