Checking power supply

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Secondary Air Pump Relay Terminals

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Connect multimeter as follows to measure voltage.

Relay carrier in electronics box, plenum chamber, position 2 Terminal	Measure to
1	Engine ground
2	Engine ground

Specified value: approx. battery voltage

If specified value is not attained:

Check wiring connections.

Refer to Electrical Wiring Diagrams, Troubleshooting & Component Locations