Throttle Full Close Switch: Testing and Inspection

Note: The Closed Throttle Position (CTP) switch is located in the Throttle Position (TP) sensor housing.

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
- Select "Read measuring value block" function 08 using VAG 1551 Scan Tool.
- Input display group number 04.
- Observe display values in channel 4, while performing the following:
- Apply Accelerator Pedal slightly (a few millimeters). Two digits of the 5-digit display number, must change:
^ 3rd digit: changes from 0 to 1
^ 4th digit: changes from 1 to 0

If value changes (but only after additional pedal travel):
- Adjust CTP switch.

If display does NOT change:
- Check CTP switch and wiring connections.

If digits have already changed prior to accelerator pedal application:
^ 3rd digit already changed to 1
^ 4th digit already changed to 0
- Adjust CTP switch.

If after adjusting, fault is still present:
- Check CTP switch and wiring connection.

Electrical Check

- Disconnect Throttle Position (TP) sensor connector.
- Set Digital Volt Ohm Multimeter (DVOM) to resistance range.

Throttle Switch/Sensor Terminals:

- Connect DVOM between terminals 4 and 6 using VW 1594 connector test kit.
^ Resistance must be 0 ohms (continuity).
- Open throttle valves slightly.
^ Resistance must be infinite ohms (open).

If specified value is NOT obtained (or is obtained only after opening valves farther):
- Adjust CTP switch.

If specified value is still NOT obtained after adjusting CTP switch:
- Replace TP sensor.

Adjusting

Note: Adjusting the CTP switch automatically adjusts the TP sensor.

- Loosen both TP sensor housing screws.

Throttle Switch/Sensor Adjusting:

- Turn TP sensor in direction shown (arrow) until stop is reached.
^ Throttle valve (throttle linkage) must NOT be moved.
- Tighten TP sensor screws in this position.
- Check CTP switch again.

Checking wiring from TP sensor to ECM

- Connect VAG 1598 Test Box to Engine Control Module (ECM) wiring harness using VAG 1598/5 adapter cable. Refer to VAG 1598 Pin Out Box Connecting Connecting and Testing VAG 1598 Pin Out Box
^ ECM remains disconnected.
- Disconnect TP sensor harness connector.

6-Pin Connector:

- Using wiring diagram, check following circuits for continuity or shorts, by testing at terminals indicated:
^ Must be 1.0 ohm maximum.

TP sensor harness VAG 1598
connector terminal socket number
number
4 9
6 52

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

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