Wiring to Transmission Control Module

CHECKING WIRING CONNECTIONS TO TRANSMISSION CONTROL MODULE

Checking input signal for selector lever position

By using this signal, idle speed is reduced by about 50 RPM when a driving mode is selected.

Requirements

^ Engine Control Module (ECM) coding OK

Test Procedure

- Switch ignition on.
- Using VAG 1551, Select "Engine electronics" address word 01 and initiate "Read Measuring Value Block" function 08, display group 004 and observe display field 4. Testing and Inspection

- Display will appear as shown:

Read Measuring Block Value 4
1 2 3 4

- Observe fourth digit of 4-digit display (switch inputs) in display field 4.
^ Specified value: XXX 1

NOTE:
The switch inputs indicated by digits 1,2 and 3 are ignored for this test.

- Select driving mode.
^ Specified value: XXX 0

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

If the display does not change even though coding is correct:

- Connect VAG 1598 test box with VAG 1598/11 adapter harness to ECM.
^ Connector D of wiring harness must be connected to ECM.
- Connect VAG 1 527B voltage tester to test box sockets 32 and 45 (Ground).
- Switch ignition on.
^ LED must light up when a driving mode is engaged.

If LED does not light up:

- Disconnect connector -B- of ECM wiring harness from VAG 1598/11 adapter harness.

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

^ Short to Ground (GND) in wiring between ECM connector B terminal 12 and to TCM -J217-.
^ Malfunction in TCM -J217- (short circuit to GND is not corrected by selecting a driving mode.)

If LED does not light up with connector B disconnected (regardless of whether a driving mode P or N is selected):

- Replace ECM.

If LED lights up when connector B is connected and does not go out when selecting a driving range, the following malfunctions could be present:

^ Break in wiring between ECM connector B terminal 12 and TCM -J217-.
^ Malfunction in TCM -J217- (no short circuit to GND in P or N).
- If necessary, check and repair wiring using wiring diagram and check TCM or shift lock solenoid.

Checking input signal for shifting

This signal retards the ignition timing briefly while changing gear in order to reduce shift force.

WARNING!
This test can be carried out only during a road test with help from a second technician.

Requirements
^ Engine Control Module (ECM) coding OK

Test Procedure
- Read measuring value block (VAG 1551 function 08), display group 000 during the road test.
^ Value in display field 7 must be briefly increase by 2 while shifting

If the display does not change even though coding is correct, perform following tests on a stationary vehicle:

- Connect VAG 1598 test box to ECM using VAG 1598/11 adapter harness.
^ Connector D of wiring harness must be connected to ECM
- Connect VAG 15278 voltage tester to test box sockets 33 and 45 (Ground). Connecting VAG 1598/31 Test Box
- Switch ignition on.
^ LED must light up

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

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

^ Short circuit to Ground (GND) in wiring between ECM connector B terminal 13 and TCM.
^ Malfunction in TCM (permanent short circuit to GND)

If LED does NOT light up when connector -B- is disconnected:
- Replace ECM.

If LED lights up when connector -B- re-connected:

- Bridge test box sockets 33 and 45 for approx. 2 to 3 seconds.
^ Value in display field 7 must be briefly increased by 2 If the display does NOT change:
- Replace ECM.

If the value displayed in display field 7 changes, the following malfunctions may be present:

^ Break in wiring between ECM connector B terminal 13 and TCM.
^ Malfunction in Transmission Control Module (no short circuit to GND when shifting).
- If necessary, check and repair wiring break using wiring diagram, or check TCM.

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:
^ 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.