Transmission Position Sensor/Switch: Testing and Inspection

NOTE: The Engine Control Module (ECM) uses this signal to recognize the transmission range selector lever position. When a driving mode is selected, idle speed should drop by approx. 50 RPM to reduce creep.


Checking requirement
- Control module coding OK, Refer to "Code Control Module, under On Board Diagnostic (OBD)-Multiport Fuel Injection (MFI)". Code Control Module (Function 07)
- Switch ignition ON.
- Using VAG 1551 scan tool, select "Read Measuring Value Block" function 08, display group 004, display field 4, refer to "Read Measuring Value Block (Function 08)". Read Measuring Value Block (Function 08)

Indicated on display


Read measuring value block4 ->
1 2 3 4

Specified value: XXX_1X (TR selector lever in P or N)
- Apply brake and select drive mode (1, 2, 3, R or D).
Specified value: XXX_0X


CAUTION!
Do not use the shift inputs (identified by an X) during the selector lever position check.


- Press -> button.
- Select "End Output" function 06 and press -Q- button to confirm input.

If a display did NOT change, even though coding is OK:
- Connect VAG 1598/19 test box to ECM harness connector.
- Connect VAG 1527B voltage tester between test box sockets 11B (signal) and 10B (constant B+/terminal 30).
- Voltage tester must light up (with TR selector lever in P or N), then go out with drive mode (1, 2, 3, R or D) selected

If voltage tester lights up and goes out when drive mode is selected, even though the range indicator in the "Read measuring value block" is OK:
- Replace ECM.

If voltage tester lights up constantly or not at all:







- Check wiring for short to ground, short to B+ or open circuit between ECM terminal 11B and multi-function switch, using wiring diagram.

If wiring is OK:
- Check multi-function switch.