Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1991 Audi 100 BaseFACTORY OEM SERVICE PROCEDURE
Secondary Resistance
- Check power stage ground wire, and wiring between power stage and ignition coil for corrosion or damage. On version 1, disconnect ignition coil power stage connector and ignition coil wire. See Figure .
- On version 2, disconnect ignition coil power stage connector and remove screw from top of assembly. See Figure . On both versions, connect Multimeter (US 1119) between ignition coil positive (+) terminal and coil wire socket. See Fig 1 and Fig 2 .
- Resistance should be 5000-9000 ohms. If resistance is not as specified, replace ignition coil.
Factory Service Tools
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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.