Checking actuation of fuel pump relay: Audi A3 1.6 (APF, AVU, BFQ)

🧭 Before you start

Fits: Audi A3 (8L, 1996–2003)

• Special tools named: V.A.G 1598/31, V.A.G 1594
• Renewed: engine control unit

Don't miss

• Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect engine control unit .

🔧 Engine codes this applies to

📐 19 workshop diagrams for APF

Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.

📋 Procedure

1. Switch off ignition.
2. Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect engine control unit .
3. Use leads from adapter set V.A.G 1594 A to bridge contacts 1 and 80 at test box.
4. Switch on ignition.
5. Replace engine control unit .

6. Disconnect cable jumper.
7. Switch off ignition.
8. Detach fuel pump relay.
9. Connect the multimeter to contact 19 of relay socket and earth to measure voltage.
10. Switch on ignition.
11. Check the wiring connections. "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations"
12. Switch off ignition.
13. Check for open circuit and short to positive or earth in the following wiring connections:
14. Rectify any open/short circuit as necessary.
15. Replace the fuel pump relay J17.
16. Reconnect engine control unit.

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