Throttle Position Sensor: Testing and Inspection
Throttle Position (TP) sensor, checking
Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram
Test requirement
- The respective fuses of Motronic Engine Control Module (ECM) -J220- 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
NOTE: When servicing terminals in the harness connector for the Throttle Position (TP) Sensor, use only gold-plated terminals.
- Remove footwell cover (driver's side).
- Disconnect 6-pin connector from Throttle Position (TP) Sensor.
- Switch ignition on.
Checking voltage supply and wiring to control module
- 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:
- Connect test box to control module wiring harness. connect test box for wiring test. Test Box, Connecting 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 ohms
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: Infinite ohms
If no malfunction is detected in the wiring and if the voltage supply was OK:
- Replace Throttle Position (TP) sensor. item 4.
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes