volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Checking function of open Haldex coupling > < Checking function of Haldex coupling - vehicles with dual clutch gearbox
Checking function of closed Haldex coupling
Checking function of closed Haldex coupling
Test preconditions
t  Oil level of Haldex coupling OK.
t  Check oil level in Haldex coupling → Chapter.
t  Correct engine control unit and ABS control unit installed (check coding and control unit identification numbers).
–  Put vehicle on lifting platform.
  Caution
For reasons of safety, vehicle must be placed on lifting platform so that wheels have no contact with the ground.
Carry out test with care to avoid damage.
–  Start engine.
–  Select driving range D and take foot off brake pedal
All four wheels must now turn.
–  Apply handbrake.
–  Accelerate slightly.
It must be possible to feel or see the wheels attempt to drive against the handbrake.
l  If the wheels attempt to drive against the handbrake:
The Haldex coupling is closed and function is OK.
l  If no attempt of the wheels to drive against the handbrake is observed:
Haldex coupling is open. Possible cause of fault
t  Main pressure regulating valve might be stuck
t  Mechanical defect in Haldex coupling
t  Four-wheel drive control unit -J492- on rear final drive defective.
   

Checking function of open Haldex coupling > < Checking function of Haldex coupling - vehicles with dual clutch gearbox