Throttle Position Sensor: Testing and Inspection

Note: The Throttle Position (TP) sensor is located on the throttle body.

Requirement
^ Accelerator pedal cable adjustment OK

Function Test with VAG 1551
- Connect VAG 1551 scan tool. Refer to Connecting and Operating VAG 1551 Scan Tool Connecting and Operating VAG 1551 Scan Tool
- Switch ignition ON.
^ Do not start engine.
- Select "Read measuring value block" function 08 using VAG 1551 Scan Tool.

Note: Do not allow engine to idle.

- Input display group number 03.
- Observe display values in channel 3, under the following conditions:
Closed Throttle Position (CTP): accelerator pedal not applied:
^ Display value must be 5°-10°.
Wide Open Throttle (WOT): accelerator pedal pressed to floor:
^ Display value must be 9°-102°.

Note:
^ For values less than 5° there is a short circuit in the wiring connection to TP sensor.
^ For values over 102° there is an open circuit in the wiring, or in the TP sensor.

If specified values are NOT obtained:
- Check TP sensor adjustment, and correct if necessary.

If adjustment is OK:
- Check voltage supply.
- Check wiring connection.
- Check TP sensor resistance.

Checking voltage supply
- Disconnect harness connector from TP sensor.
- Switch ignition ON.
- Connect Digital Volt Ohm Multimeter (DVOM) between terminals 1 and 2.
^ Must be 4.5-5.5 volts.
- Connect Digital Volt Ohm Multimeter (DVOM) between terminals 2 and 3.
^ Must be 4.5-5.5 volts.

If YES:
- Check resistance of TP sensor.

If NO (one or both specified values NOT obtained):
- Check ECM and ECM wiring.

Checking wiring and connections
- Switch ignition OFF.
- Connect VAG 1598 Test Box to Engine Control Module (ECM) wiring harness using VAG 1598/5 adapter cable.
^ ECM remains disconnected.
- Using wiring diagram, check following circuits for continuity or shorts, by testing at terminals indicated:

Connector VAG 1598
terminal socket number
1 12
2 30
3 53

^ Must be 1.0 ohm maximum.

- Repair open or short circuits as necessary, using wiring diagram.

Note: Use only gold replacement terminals when making repairs to TP sensor connectors.

- Connect VAG 1598/5 adapter cable to ECM.
- Switch ignition ON.
- Connect DVOM between terminals 12 and 30.
^ Must be 4.5-5.5 volts.
- Connect DVOM between terminals 30 and 53.
^ Must be 4.5-5.5 volts.

If NO (one or both specified values NOT obtained):
- Replace ECM.

Checking TP sensor resistance
- Using VW 1594 connector test kit, connect DVOM to following terminals, in turn:
Terminals 1 and 2:
^ Must be 1500-2600 ohms.
Terminals 2 and 3:
^ Must be 750-1300 ohms.

- Measure resistance again while bringing throttle lever slowly to Wide Open Throttle (WOT) position.
^ Must increase to 3600 ohms maximum.

If NO (for one or both circuits):
- Replace TP sensor.

Adjusting

Note: Adjusting the Closed Throttle Position (CTP) switch automatically adjusts the TP sensor.