Electric coolant fan, checking: Notes
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2009 Audi S4, 2008 Audi S4, 2007 Audi S4, 2006 Audi S4, and 2005 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.
Special tools, testers and auxiliary items required
- Hand multimeter V.A.G 1526 B or V.A.G 1526 A
- Voltage tester V.A.G 1527 B
- Connector test kit V.A.G 1594 C or V.A.G 1594 A
- Test box V.A.G 1598/31
- Vehicle Diagnostic, Testing and Information System VAS 5051 with diagnostic cable VAS 5051/1
Work sequence
- Connect Vehicle Diagnostic, Testing and Information System VAS 5051 A and select vehicle system "01 - engine electronics". For this, ignition must be switched on Guided Fault Finding in VAS 5051.
Display on VAS 5051 :
- In selection - 1 - , click on the function "03 - output Diagnostic Test Mode (DTM)".
- Press → button repeatedly, until "coolant fan activation 2" is activated.
- Coolant Fan Control (FC) Control Module 2 J671 switches on Coolant Fan 2 V177 (right) 1 time slowly to full speed.
- Press → button repeatedly, until "coolant fan activation 1" is activated.
- Coolant Fan Control (FC) Control Module J293 switches on Coolant Fan V7 (left) 1 time slowly to full speed.
- End function "03 - output Diagnostic Test Mode (DTM)" by pressing ← button.
If fan activation does not react as described:
- Produce conditions for starting up coolant fan according to required input criteria (e.g. switch on A/C system, increase engine temperature correspondingly).
Display on VAS 5051 :
- In selection - 1 - , click on function "08 - Read measuring value block".
Display on VAS 5051 :
1 - Enter display group
- Select function "135" in button field - 2 - for "display group 135" and press Q to confirm input.
Display on VAS 5051 :
- Check indication in display fields - 2 - and - 3 -.
| Display field | Indicated | Specified value |
|---|---|---|
| - 2 - | Duty cycle for fan 1 (left) in % | min. 10% |
| - 3 - | Duty cycle for fan 2 (right) in % | min. 10% |
NOTE:
- At fan request by A/C system and/or coolant temperature greater than 98 ° C, duty cycle must rise above 10% and fans must start up.
- Press ← button to end function "08 - Read measuring value block".
If duty cycle does not rise above 10%:
- Read out DTC memory of engine control module (ECM).
- Select "06 - End Output".
- Switch off ignition.
- Repair displayed malfunctions if necessary.
If respective fan does not start up even though duty cycle is above 10%:
- Check Coolant Fan V7 or Coolant Fan 2 V177.