Throttle Full Close Switch: Testing and Inspection

NOTE:
- To functionally check the Closed Throttle Position (CTP) switch, See Read measuring value block, display group 002, display field 4.
- The Closed Throttle Position (CTP) switch is located in the Throttle Position (TP) sensor assembly.
- Component locations, refer to "Component Overview - II", Locations
- If, while checking or adjusting the Closed Throttle Position (CTP) switch, the noise deadener is removed; make sure during re-assembly that there is a tight fit to the throttle body to avoid the possibility of an intake air leak.
- For safety, make sure that the Mass Air Flow (MAF) sensor output voltage is correct, refer to "Basic Setting (Function 04)". Basic Setting (Function 04)


Requirements
- Accelerator pedal cable adjustment OK.

Electrical check
- Remove intake air sound absorber.
- Disconnect harness connector at throttle body.







- Switch multimeter (Fluke 83 or equivalent) to measure resistance (ohms) and connect between terminals 4 and 6 using jumper wires from connector test kit VW 1594.
- Specified value: 0 ohms (continuity)
- Open throttle slightly.
- Specified value: infinity ohms (no continuity)

If the specified value is not obtained by opening the throttle slightly, or if the specified value is obtained only by moving the throttle:
- Adjust CTP switch. See Adjusting.

If, after adjusting the CTP switch, it is still not possible to obtain the specified function:
- Replace throttle position sensor assembly.

Adjusting
- Remove throttle body.
- Loosen two throttle position sensor mounting screws.







- Turn throttle position sensor in direction shown (arrows), without moving throttle valve shaft, until stop can be felt.
- Tighten throttle position sensor in this position.
- Check CTP switch again refer to Closed Throttle Position (CTP) Switch, Checking and Adjusting
- Re-install throttle body and adjust accelerator pedal cable.

Checking wiring between CTP switch and ECM







Terminal assignments for throttle position sensor connector.
- Connect VAG 1598/19 test box to ECM harness connector.
- Check wiring for continuity or short to B+ between throttle position sensor connector terminal 4 (GND) and test box socket D12.
- Specified value: max. 1 ohms (ohms)
- Check wiring for continuity or short to Ground (GND) between throttle position sensor connector terminal 6 (signal) and test box socket A4.
Specified value: max. 1 ohms

If the specified value is not obtained:







- Determine open or short circuit in wiring using wiring diagram; repair as necessary.

6-pin TP sensor ECM connector A
connector terminal terminal
6 A4
4 Intake manifold Ground (GND)


NOTE: If it becomes necessary to repair or replace any of the throttle position sensor electrical terminals, ONLY replace with gold-plated terminals.