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
Fuel Pump Relay (2.2L)
- Remove fuel pump relay from relay board. Turn ignition on. Test light should light when connected between pump relay terminal No. 46 and ground. See Fig 1 .
- While starter motor is operating, test light should flicker when connected to relay terminals No. 50 and No. 51. Test light should light when connected between relay terminals No. 46 and No. 50, and relay terminals No. 46 and No. 52.
- If test light does not light for all tests, check wiring for short or open. If test light lights for all tests but there is no voltage at fuel pump with relay installed, replace fuel pump relay.
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.