Mac11 ECU Graphical Pin Out Diagram

1986-88 5000TQ, Early 1989 200T/Q with single knock sensor MC engine.

Note: The "Indicator Light" shown in the top/right area of the diagram, is the "Check Engine" light in the instrument panel.

The fuel pump relay diagram shows the two contacts (o) for the fuse that is used to start the fault code retrieval sequence. One of the these fuel pump relay fuse contacts (o) is grounded, as shown by the _|_ symbol.

When you insert the fuse into the fuel pump relay contacts for 4 seconds, effectively you are grounding terminal 31 on the ECU which starts the fault code sequence, and it also grounds the "Check Engine" light to turn it on. After 4 seconds, you remove the fuse, and then the ECU will begin grounding the "Check Engine" light to blink out the fault codes.

The switch shown connected to the battery with terminals 30 and 15, is the ignition switch.

ECU Graphical Pin Out Diagram, courtesy of Audi of America, Service training booklet

"1986 Model Change Information"

The ECU ground connections at the bottom of this diagram are pins 18 and 9.

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