Checking fuel system pressurisation pump G6 (0.5 bar high-pressure pump) — AUDI

🧭 Before you start

Observe the test conditions, remove the filler cap and let the fuel cool before disconnecting the supply line. Connect VAS 6551 with its hose and pressure control valve, open valves A and B with C closed, and actuate the pump from the diagnostic tester. Set the pressure with the adjuster screw, stop, empty the container, then run for 15 seconds and check the delivered quantity.

Fits: Audi A1 (8X, 2010–2018)

• Opens: fuel
• Special tools named: VAS 6551

Don't miss

• Fuel and lines can reach 100 °C after shutdown; allow them to cool and wear gloves and goggles.
• Cut-off valve C must be closed, lever across the flow, or fuel escapes.
• Once pressure is set, do not touch the adjuster screw again for the measurement.
• Empty the measuring container before the timed 15-second run.
• Wrap a cloth around the connection and loosen it slowly to release pressure.

Written for this job from the workshop steps below · TorqFix editorial.

🔧 Engine codes this applies to

📐 83 workshop diagrams for CAYB

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

📋 Procedure

1. Observe test conditions .
2. Remove filler cap (arrow) for fuel filler neck.
3. ⚠ The fuel can become extremely hot. This can cause injuries.In extreme cases the temperature of the fuel lines and the fuel can be up to 100 °C after the engine is switched off. Allow the fuel to cool down before disconnecting the lines - danger of scalding.Wear protective gloves.Wear safety goggles.Risk of injury - fuel system operates under high pressure.To reduce the pressure in the fuel system, wrap a clean cloth around the connection and carefully loosen the connection. — Disconnect fuel supply line (1). Disconnecting plug-in connectors
4. Disconnect fuel line (2). Disconnecting plug-in connectors
5. Connect pressure tester (diesel)VAS 6551 to fuel supply line with hoseVAS 6551/2.

6. Attach pressure control valveVAS 6551/6 and hold end of hose into fuel-resistant measuring container.
7. Switch on pressure tester (diesel)VAS 6551(item 1) by pressing On/Off button. [Note: To measure the fuel delivery rate, pressure must first be built up in the fuel supply line; the fuel pump must then operate against this pressure during the measurement. This pressure can be built up using the pressure control valveVAS 6551/6 as follows:]
8. Open cut-off valves (A and B).
9. ⚠ Risk of fuel escaping.Cut-off valve (C) must be closed.The lever should point perpendicular to direction of flow. — Connect vehicle diagnostic tester.
10. Switch on the ignition and select the following menu options on the vehicle diagnostic tester:
11. Press Start: The fuel pump will start running.
12. Build up pressure in fuel system by turning adjuster screw (1) on pressure control valveVAS 6551/6 until correct pressure is reached.
13. From this point on, do not turn adjuster screw (1).
14. Press Stop.
15. Drain measuring container.
16. For measurement, press Start again and let fuel pump run for 15 seconds.
17. Press Stop after 15 seconds.
18. Check amount of fuel delivered in measuring container.

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