Wiring to Transmission Control Module

CHECKING INPUT SIGNAL FOR SELECTOR LEVER POSITION
This signal reduces the idle speed by approx. 50 RPM when the automatic transmission is in a DRIVE mode.

REQUIREMENTS
- Fuses for engine electronics OK
- Fuel pump relay OK.
- Ground connections OK.
- Engine Control Module (ECM) coding OK.

PROCEDURE
- Connect VAG 1551 scan tool. Refer to Connecting and Operating VAG Scan Tool.
- Switch ignition on.
- Initiate "Read Measuring Value Block" function 08 and select display group 004. Display will appear as shown:

Read measuring value block 4
1 2 3 4

- Observe display value in display field 4.
^ Specified value: XXX 1 X (selector lever in P or N).
- Move selector lever to Drive.
^ Specified value: XXX 0 X.

NOTE: The shift inputs at positions designated with "X" are not considered for checking selector lever position recognition.

- Press "arrow" button.
- Press -0- and -6- buttons to select "End Output" function 06.
- Press -Q- button to confirm input.

If the display does not change although the coding is OK:
- Connect VAG 1598 test box to ECM using VAG 1598/11 adapter harness. Refer to
^ Harness connector D must be connected to the ECM.

Engine Control Module (ECM) Connectors:

- Connect VAG 1527B voltage tester between test box socket 32 and Ground (GND).
- Switch ignition ON.
^ LED must light up when drive is selected.


If LED does not light up:
- Disconnect harness connector B of the vehicle wiring harness from VAG 1598/11 adapter harness.

If LED now lights up, the following malfunctions are possible:
- Short circuit to Ground (GND) in the wiring between ECM connector B terminal 12 and Transmission Control Module (TCM) -J217-.
- Malfunction in TCM -J217-; short-circuit to GND is not eliminated when drive mode is selected.

If LED does not light up with harness connector B disconnected (independent of the selector lever position):
- Replace ECM.

If LED lights up when harness connector B is connected and does not go out when a driving mode is selected, the following malfunctions are possible:

Engine Control Module (ECM) Connectors:

- Open circuit in wiring between ECM connector -B- terminal 12 and TCM -J217-.
- Malfunction in TCM -J217-; no Ground connection in PARK/NEUTRAL.

If necessary, check for open circuit in wiring using wiring diagram and repair as needed; check TCM and/or selector lever switch, repair or replace as necessary.

CHECKING SMOOTH SHIFT SIGNAL
Because of this signal, the ignition angle is briefly retarded during shifting to decrease jerking during shifting.

Test Requirement
^ Engine Control Module (ECM) coding OK.

WARNING!
For testing during a road test, the scan tool must be operated by a second technician.
- Perform test drive and in the process, access "Read Measuring Value Block", function 08 via the VAG 1551 scan tool and select display group 000. Display will appear as shown:

Read measuring value block 0
1 2 3 4 5 6 7 8 9 10
- Observe values in display field 7.
^ In shift mode, displayed value must briefly increase by 2.

If this change in value does not take place although the coding is OK, carry out the following tests with ignition switched OFF:
- Connect VAG 1598 test box to ECM using VAG 1598/11 adapter harness.
^ Connector D of the vehicle wiring harness must be connected to the ECM.
- Connect VAG 1527B voltage tester between test box socket 33 and Ground (GND).
- Switch ignition ON.
^ LED must light up.

If LED does not light up:
- Disconnect vehicle wiring harness connector B from VAG 1598/11 adapter harness.

If LED now lights up, the following malfunctions are possible:

Engine Control Module (ECM) Connectors:

- Short circuit to Ground (GND) in the wiring between ECM connector -B- terminal 13 and Transmission Control Module (TCM) -J217-.
- Malfunction in ECM or TCM; continuous short circuit to GND.

If LED does not light up with connector -B- disconnected:
- Replace ECM.

If LED lights up with connector B reconnected:
- Connect test box socket 33 to GND for approx. 3 seconds.
^ Value in display field 7 must briefly increase by 2.

If the displayed value does not change:
- Replace ECM.

If the displayed value in display field 7 changes, the following malfunctions are possible:

Engine Control Module (ECM) Connectors:

- Open circuit in wiring between ECM connector -B- terminal 13 and TCM.
- Malfunction in TCM (no connection to Ground during shifting).

Check wiring using wiring diagram and repair and/or check ECM.