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Test modulating piston movement sender G149 and metering adjuster N146 > < Test coolant temperature sender G62

Octavia Mk1

Test brake light switch and brake pedal switch
Test brake light switch and brake pedal switch
As the injection system operates with an accelerator pedal position sender (potentiometer), which may become defective, for reasons of safety the engine is cut-off when the brake is activated. To do so the brake light switch signal and additionally the brake pedal switch signal in the engine control unit is required. This means that if the brake pedal is activated with the accelerator pedal constantly pressed, the engine immediately slows down to idling speed. Unclean switch settings may result in involuntary cut-off procedures.
Special tools and workshop equipment required
t  Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3-
Test sequence
–  Connect vehicle system tester -V.A.G 1552- and activate the function “read measured value block” → Chapter.
–  Read measured value block, display group 006, engine at idling speed → Chapter.
   
–  Readout on display:
–  Observe display in display field 2.
  
Reading measured value block   6   ->
0 km/h      0 0 0       000000        0
Specified value: 0 0 0
–  Slowly operate the brakes.
  
Reading measured value block   6   ->
0 km/h      0 0 0       000000        0
Specified value: 0 1 1
Both displays must switch from 0 to 1.
t  middle display = brake pedal switch
t  right display = brake light switch
–  Slowly return the brake pedal back into the off position.
  
Reading measured value block   6   ->
0 km/h      0 1 1       000000        0
Specified value: 0 0 0
Both displays must switch from 1 to 0.
If one of the displays or both switch from 0 to 1:
–  Test switch or cable connections to the switches → Current flow diagrams and Fitting locations.
  
Reading measured value block   6   ->
0 km/h      0 0 0       000000        0

Test modulating piston movement sender G149 and metering adjuster N146 > < Test coolant temperature sender G62