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Checking voltage supply and wiring to control unit > < Function of EPC system

Golf Mk4

Checking accelerator pedal position sender
   
Checking accelerator pedal position sender
Special tools and workshop equipment required
t  Hand multimeter -V.A.G 1526 A- or hand multimeter -V.A.G 1526C-
t  Auxiliary measuring set -V.A.G 1594 A- or auxiliary measuring set -V.A.G 1594C-
t  Adapter lead, 121-pin -V.A.G 1598/31-

Not illustrated:
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- or vehicle diagnosis and service information system -VAS 5052-
t  Current flow diagram
Function
Both accelerator pedal position sender -G79- and accelerator pedal position sender 2 -G185- are located on the accelerator pedal and transmit the driver's requirements to the engine control unit completely independently of each other. Both senders are installed together in one housing.
Test procedure
–  Connect fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- or vehicle diagnosis and service information system -VAS 5052- and select the engine control unit with “Address word” 01. The ignition must be switched on for this purpose: → Rep. Gr.01.
   
Indicated on display:
–  Press keys 0 and 8 for function “Read measured value block” and confirm entry with Q key.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Press keys 06 and 2 for “Display group number 62” and confirm entry with Q key.
  
Read measured value block            HEL
Input display group number XXX
Indicated on display: (1...4 = display zones)
–  Check reading from accelerator pedal position sender -G79- at idling speed stop in display zone 3. Specification: 6…96 %.
–  Check reading from accelerator pedal position sender 2 -G185- at idling speed stop in display zone 4. Specification: 3…48 %.
  Note
The engine control unit calculates the angle sender voltage values as a percentage in relation to 5 volts and displays this percentage figure. (5 volt supply voltage equates to 100 %).
–  Press the accelerator pedal slowly to full throttle position and note the percentage figure in display zones 3 and 4 when doing this:
The percent figure in display zone 3 must rise evenly. The tolerance range of 6...96 % is not covered completely.
The percent figure in display zone 4 must rise evenly. The tolerance range of 3...48 % is not covered completely.
  Note
The figure shown in display zone 3 must always be approximately double the figure shown in display zone 4.
–  Press the → key.
–  Press keys 0 and 6 for function “End output” and confirm entry with Q key.
–  Switch off ignition.
If the displays are not as described:
–  Check the power supply and wiring connections to the accelerator pedal position senders → Chapter.
  
Read measured value block 62           -
         1         2         3         4

Checking voltage supply and wiring to control unit > < Function of EPC system