Audi Workshop Service and Repair Manuals

Testing activation of output stages

Note:

It is important to ensure that no fuel is injected during the test as this would damage the catalytic converter. The connectors on the injectors must therefore be unplugged.

• ‒ → Unplug 5-pin connector -1- from output stage -2- for ignition coils.

• ‒ → Connect voltage tester V.A.G 1527 B as follows:

• ‒ Operate starter for a few seconds.
• ‒ The LED should flicker.

If the specifications are not obtained:

• ‒ Switch off ignition.
• ‒ Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
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• ‒ → Test for open circuit and short to positive or earth in the following wiring connections:

• ‒ Rectify any open/short circuit as necessary.

If no fault is detected in the wiring:

• ‒ Connect 5-pin connector to output stage.
• ‒ Unplug 4-pin connector from output stage.

• ‒ Connect voltage tester V.A.G 1527 B to battery positive (+) and to one of the contacts on the 4-pin output connection on the ignition output stage.

• ‒ Operate starter for a few seconds.
• ‒ The LED should flash.

If the LED does not flash when testing one or more of the output connections:

• ‒ Renew output stage.