Throttle Position Sensor, Checking

Special tools and workshop equipment required 

• Multimeter VAG1526 or multimeter VAG1715
• Connector test kit VAG1594
• Wiring diagram

Test requirements 

• Fuses in E-box (in plenum chamber, left) must be OK: Refer to SYSTEM WIRING DIAGRAM
  Fig 1: Identifying Fuses In E-Box (In Plenum Chamber, Left)

  Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
• Battery voltage must be at least 11.5 volts.
• All electrical consumers such as, for example, lights and rear window defroster must be switched off.
• Parking brake must be engaged or else daylight driving lights will be switched on.
• For vehicles with automatic transmission, selector lever must be in P position.
• If vehicle is equipped with an A/C system, it must be switched off.
• Ground (GND) connections between engine and chassis must be OK.

Function 

Both the Throttle Position (TP) Sensor -G79- and the Sender -2- for accelerator pedal position -G185- are located at the accelerator pedal and communicate the driver's intentions to the ECM completely independently of each other. Both sensors are stored in one housing.

Test sequence

-- Remove footwell cover (driver's side).

-- Disconnect 6-pin connector from Throttle Position (TP) Sensor.

-- Switch ignition on.

Checking voltage supply 

-- Connect multimeter to the following connector terminals for voltage measurement.

Terminal 1 + Ground (GND)

Terminal 1 + 5

Terminal 2 + Ground (GND)

Terminal 2 +3

Specified value: at least 4.5 V

-- Switch ignition off.

If specified values are not obtained:

-- Check wires according to wiring diagram.

Checking wiring 

-- Connect test box to control module wiring harness, connect test box for wiring test.

-- Check wires between test box and 6-pin connector for open circuit according to wiring diagram.

Terminal 1+socket 72

Terminal 2+socket 73

Terminal 3 + socket 36

Terminal 4 + socket 35

Terminal 5 + socket 33

Terminal 6 + socket 34

Wire resistance: max. 1.5 Ω

-- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.

Specified value: ∞ Ω

-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.

-- Generate readiness code.

If no malfunction is detected in the wiring and if the voltage supply was OK:

-- Replace Throttle Position (TP) sensor.

-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.

-- Generate readiness code.