With Manufacturer's Scan Tool
Throttle Position (TP)sensor -G79- / Sender 2 for accelerator pedal position - G185-, checking
Special tools and equipment
^ VAG 1526 A Hand multimeter
^ VAG 1594 A Adapter set
^ VAG 1598/31 Test box
^ V.A.G 1551 Scan Tool or vehicle system tester V.A.G 1552 with cable VAG 1551/3A
Note: All functions which could previously be performed with V.A.G. 1551/1552 can also be performed with the new tester VAS 5051.
^ Wiring diagram
Note: Only gold plated contacts may be used to service the contacts in the TP sensor/ Sender for accelerator pedal position connection.
Function
Both the Throttle Position (TP) sensor -G79- and the Sender 2 for accelerator pedal position -G185- are located on the accelerator pedal and pass the driver's requirements on to the engine control module independently of one another. Both are installed together in a housing.
Test conditions
^ Fuses must be OK.
^ Battery voltage must be at least 11.5 V
^ All electrical consumers, e.g. lights and rear window defroster must be switched off.
^ If the vehicle is equipped with air conditioning, this must be switched off.
^ Selector lever must be in position "P" or "N" on models with an automatic transmission.
Test sequence
- Connect V.A.G 1551 Scan Tool (or V.A.G 1552) and select engine electronics control module with the "Address word" 01. Ignition must be switched on when doing this:
Refer to Powertrain Management
Indicated on display
- Press keys O and 8 for function "Read measured value (data) block" and confirm entry with Q key.
Indicated on display
- Press keys 0, 6 and 2 for "Display group number 62" and confirm entry with Q key.
Indicated on display: (1 . . .4 = display zones)
- Check specifications of TP sensor -G79- at idling speed limit stop in display zone 3.
Specification: 12...1 7%
- Check specifications of Sender 2 for accelerator pedal position -G185- at idling speed limit stop in display zone 4
Specification: 4...1 0%
Note: The engine control module calculates the angle sender voltage value as a percent of 5 Volts and displays this percentage. (5 volt supply voltage equals 100%).
- Depress accelerator pedal slowly until fully depressed and observe percentage figures in display zones 3 and 4:
The percentage display in display zone 3 must increase evenly. The tolerance range 12...97% is not fully exploited.
The percentage display in display zone 4 must increase evenly. The tolerance range 4...49% is not fully exploited.
Note: The figure displayed in display zone 3 must always be approximately double the value displayed in display zone 4.
- Press (arrow) key.
- Press keys O and 6 for function "End output" and confirm entry with Q key.
- Switch ignition off.
If the displays do not indicate as described:
- Check Throttle Position (TP) sensor -G79- and Sender 2 for accelerator pedal position -G185voltage supply and wiring connections.
Checking voltage supply and wiring to control module
- Remove cover in foot well (driver's side).
- Pull 6-pin connector from TP sensor / Sender for accelerator pedal position.
- Switch ignition on.
- Connect multimeter to following connections to measure voltage using adapter cables from VAG 1594.
Contact 1 and Ground
Contact 1 and 5
Contact 2 and Ground
Contact 2 and 3
Specification: at least 4.5 V
- Switch ignition off.
- If the specifications are not attained:
- Remove wiper arms and cowl panel:
- Connect test box VAG 1598/31 to control module wiring harness. Engine control module remains disconnected.
- Check wiring for open circuit between test box and connector referring to wiring diagram.
Contact 1 and socket 72
Contact 2 and socket 73
Contact 3 and socket 36
Contact 4 and socket 35
Contact 5 and socket 33
Contact 6 and socket 34
Wire resistance: max. 1.5 Ohms
- Additionally check wiring for short to battery positive or Ground.
- Additionally check wires for short to one another.
If no wiring malfunction is detected:
- Replace TP sensor / Sender for accelerator pedal position.
- Check Diagnostic Trouble Code (DTC) memory:
Refer to Powertrain Management
- Read readiness code
- Generate readiness code again if DTC memory has been erased or engine control module disconnected from permanent positive supply:
Refer to Powertrain Management
Models with an automatic transmission
- Adapt (match) transmission control module:
Refer to Powertrain Management; Basic setting