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Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required > < Checking wiring from knock sensor to engine control unit
Checking Hall sender
Checking Hall sender
Fitting location ⇒ Fitting locations overview, Page
  Note!
t  The Hall sender is located beneath the camshaft sprocket.
t  If no Hall sender signal is received, the knock sensor signals can no longer be assigned to the cylinders. If this happens, the knock control system is deactivated and the ignition timing is slightly retarded in order to prevent knocking.
t  Even if no Hall sender signal is received, the engine will continue to run and can also be re–started. The reason for this is as follows:
t  The fact that the control unit is out of phase by one crankshaft revolution does not have any noticeable effect on the injection system.
t  The fuel is injected “upstream” of the closed inlet valve instead of while the inlet valve is open. This has only a minor influence on the quality of the air/fuel mixture.
t  With the twin spark ignition system an ignition spark is produced for each cylinder at each crankshaft revolution, and not at alternate revolutions as is normally the case.
   

Special tools and workshop equipment required > < Checking wiring from knock sensor to engine control unit