Ignition Power Stage: Testing and Inspection

CHECKING CONTROL OF POWER OUTPUT STAGES -N122- AND -N127-

4-pin Connector:

- Disconnect both 4-pin connectors from power output stages.
- Connect US 1115 LED tester or equivalent between battery positive (+) and terminal 2 (GND) of connector for right power output stage.
^ LED tester must light up.

- Connect LED tester between battery positive (+) and terminal 2 (GND) of the connector for left power output stage.
^ LED tester must light up.

If the LED tester does not light up during one or both tests:
- Check wiring connection according to wiring diagram, if necessary repair open circuit.
- Disconnect harness connectors from all five fuel injectors.
- Connect LED tester between engine Ground (GND) and (one after another) terminals 1, 3 and 4 of harness connector for left power output stage, as well as terminals 3 and 4 of harness connector for right power output stage.
- Operate starter a few seconds each time.
^ LED tester must blink.

If the LED tester does not blink:
- Connect VAG 1598 Test Box to Engine Control Module (ECM) wiring harness with VAG 1598/5 adaptor cable. Refer to VAG 1598 Pin Out Box Connecting. Connecting and Testing VAG 1598 Pin Out Box

^ ECM remains disconnected.

55-Pin Connector And 4-Pin Connector:

- Check the following terminals for continuity and/or short circuit using wiring diagrams:
- If necessary, repair open circuit and/or short circuit.

If there is neither an open circuit nor a short circuit, and the LED tester does not blink:
- Replace the ECM.