Engine Control Module (ECM) power supply checking: Checking

• Connect VAG 1598/19 test box to Engine Control Module (ECM) harness connector. See VAG1598/19 TEST BOX, CONNECTING .
• Connect VAG1527B LED voltage tester between ECM/test box socket D9 (permanent B+) and, one after the other in sequence, test box sockets D11, E7, E11 and E12 (Ground connections).
  Fig 1: Identifying ECM Connectors

  

  LED must light up in each case.

If LED does not light:

• Check wiring and connections for open circuit and repair as necessary.
• Connect VAG1527B LED voltage tester between ECM/test box sockets E7 (Ground) and B3 (Ignition, +, terminal 15).
• Switch ignition on.

  LED must light up.

• Switch ignition off.

If LED does not light:

• Check wiring and connections for open circuit and repair as necessary.