Checking Shift Procedure

NOTES:
- The Engine Control Module (ECM) uses this signal to briefly retard the ignition during shifting to reduce the mechanical jerking felt between shifts.
- The shift signal is monitored by the Transmission Control Module (TCM).
- Repair Manual, Automatic Transmission O1\4 Repair Group 01, On Board Diagnostic.

- Carry out the following check only if a shift-related DTC is stored in the TCM DTC memory.

Checking requirement
- Control module coding OK.

CAUTION: Always use a second technician to operate the VAG 1551 scan tool while driving.

- Test drive and select "Read Measuring Value Block" function 08, display group 004, refer to computers and controls, Testing and Inspection, see system diagnosis, display group diagnostic charts.

Indicated on display; note display field 4

Read measuring value block 4 -->
1 2 3 4

Specified value: XXX_X0

- Shift value must increase briefly during shifting.
Specified value: XXX_X1

NOTES: Due to its short signal duration, shifting cannot always be observed on the VAG 1551 scan tool.

CAUTION; Do not use the shift inputs (identified by an X during the shift signal check

- Press button.
- Select "End Output" function 06.
- Press -0- button to confirm input.

If the change in the shift signal display did not occur, even though the control module coding was OK:
- Connect VAG 1598/19 test box to ECM harness connector, Connecting VAG 1598/31 Test Box.
- Check wiring for open or short circuit between ECM and TCM, using wiring diagram.