Malfunction Indicator Lamp - A/T: Testing and Inspection

NOTE:
- If a malfunction is recognized by the Engine Control Module (ECM) or the Transmission Control Module (TCM), it is indicated by the Malfunction Indicator Lamp (MIL) in the instrument cluster.
- If the TCM recognizes a malfunction, the MIL is switched on via the ECM.
- The MIL wiring is monitored by the ECM.


Checking requirement
- Control module coding OK, Refer to "Code Control Module". Code Control Module (Function 07)
- Switch ignition ON.
- Using VAG 1551 scan tool, select "Read Measuring Value Block" function 08, display group 027, display field 1, refer to "Read Measuring Value Block (Function 08)" under "/Powertrain Management/Fuel Delivery and Air Induction/Testing & Inspection". Read Measuring Value Block (Function 08)

Indicated on display; note display field 1


Read measuring value block 27 ->
1 2 3 4


Specified value: 0

- Start engine and let idle.
Specified value: 1

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

If the specified value is not obtained, even though coding is OK:
- Connect VAG 1598/19 test box to ECM harness connector.
- Check wiring for open or short circuit between ECM and TCM, using wiring diagram.