WARNING: This page is about a different car, the 2001 Audi allroad, 2001 Audi S4, 2001 Audi A6, and 2001 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Set ohmmeter on 100x scale. Connect ohmmeter leads between generator output terminal and all 3 stator terminals one at a time. See Fig 1 . Reverse ohmmeter leads. If ohmmeter indicates continuity in only one direction, go to next step. If ohmmeter indicates continuity in both directions, replace diode assembly.
Connect ohmmeter leads between negative plate and all 3 stator terminals one at a time. Reverse ohmmeter leads. If ohmmeter indicates continuity in only one direction, go to next step. If ohmmeter indicates continuity in both directions, replace diode assembly.
Connect ohmmeter leads between terminal D+ (Blue wire) terminal and all 3 stator terminals one at a time. Reverse ohmmeter leads. If ohmmeter indicates continuity in only one direction, diode assembly is okay. If ohmmeter indicates continuity in both directions, replace diode assembly.

Fig 1: Testing Diode Assembly (Bosch 110-Amp Generator)
Courtesy of AUDI OF AMERICA, INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Generator Output Test

Use the Manual With the Right Hardware

When to See a Mechanic