volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

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Checking clutch pedal switch F36 > < Checking gear change signal from automatic gearbox

Golf Mk4

Checking brake light switchF and brake pedal switchF47
Checking brake light switch -F- and brake pedal switch -F47-
Because the injection system operates with an accelerator pedal sender (potentiometer) which may be defective, the engine is regulated for reasons of safety when the brakes are operated. To do this the control unit requires signals from the brake light switch and also the brake pedal switch. This means that if the brakes are operated when the accelerator pedal is held at a constant position the engine is immediately reduced to idling speed. Incorrectly adjusted switches may lead to unrequired regulating action
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with diagnosis cable -V.A.G 1551/3-
t  Adapter cable, 121-pin -V.A.G 1598/31-
t  Hand multimeter -V.A.G 1526C- or multimeter -V.A.G 1715-
t  Auxiliary measuring set -V.A.G 1594C-
t  Current flow diagram
Test procedure
–  Connect fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- and select engine electronics control unit with “address word” 01. The ignition must be switched on for this purpose. (Connecting fault reader and selecting engine electronics control unit → Chapter.)
   
Indicated on display:
–  Press buttons 0 and 8 for function “Read measured value block” and confirm entry with Q button.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Press buttons 0, 0 and 6 for “Display group number 6” and confirm entry with Q button.
–  Observe display in display zone 2.
  
Read measured value block           HELP
Input display group number XXX
Specification: 0 0 0
–  Operate brake pedal slowly.
  
Read measured value block 6          ->
0 km/h      0 0 0       0.0%         255
Specification: 0 1 1 Both displays must change from 0 to 1 at same time.
t  Middle display = brake pedal switch -F47-.
t  Right display = brake light switch -F-.
–  Release brake pedal slowly into rest position again.
  
Read measured value block 6           ->
0 km/h      0 1 1        0.0%        255
Both displays must change from 1 to 0 again.
If one or both displays do not change:
–  Check switches or line connections to the switches → Current flow diagrams, Electrical fault finding and Fitting locations
  
Read measured value block 6          ->
    0 km/h     0  0  0     0.0%     255

Checking clutch pedal switch F36 > < Checking gear change signal from automatic gearbox