Fuel Pressure, Checking:

WARNING: This page is about a different car, the 2012 Audi S5, 2011 Audi S5, 2010 Audi S5, 2009 Audi S5, and 2008 Audi S5. However, it is still accessible from the selected car via links, so may be relevant.

Battery voltage at least 12.5 Volts.
Fuel filter OK.
Fuel tank at least ¹ /₄ filled.
Fuel Pump (FP) Control Module -J538- OK
Ignition switched off.

-- Remove rear seat bench. Refer to appropriate service information. .

-- Remove the locking flange cover -arrows-.

Fig 1: Identifying Cover Bolts For Locking Flange

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-- Disconnect electrical harness connector -1- at locking flange.

Fig 2: Identifying Locking Flange Components

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NOTE:

Ignore -2-.

-- Connect the Remote Control:V.A.G 1348/3A with adapter cable :V.A.G 1348/3-3 with an adapter cable from the Connector Test Set:V.A.G 1594C at terminal -1-.

-- Cover 2nd connector terminal of Adapter Cable:V.A.G 1348/3-3 with insulating tape to prevent short circuit -arrow-.

Fig 3: Checking Fuel Pressure

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-- Connect terminal -5- to the vehicle ground using a jumper cable from the Connector Test Set:V.A.G 1594C .

-- Route Remote Control:V.A.G 1348/3A switch forward in engine compartment.

-- Connect the Remote Control:V.A.G 1348/3A to item -A- in the terminal box in the plenum chamber (battery +). For safety reasons, install a fuse (10 A) in the wiring connection.

-- Remove fuel filler cap from fuel filler tube.

-- Remove engine cover.

WARNING:

Before opening high pressure components of the fuel injection system, pressure must be relieved to residual pressure. Refer to BEFORE OPENING HIGH PRESSURE FUEL INJECTION SYSTEM .
Then wrap a clean rag around the connection and relieve residual pressure by carefully loosening the connection.

Disconnect the Fuel Supply Line arrow at the Distribution Pipe on Engines with Magnesium Intake Manifolds.

Fig 4: Disconnecting Fuel Line

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Disconnect the Fuel Supply Line arrow at the Distribution Pipe on Engines with Plastic Intake Manifolds.

Fig 5: Disconnect the Fuel Supply Line -arrow- at the Distribution Pipe on Engines with Plastic Intake Manifolds.

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-- Connect Fuel Inj. Pressure Gauge-CIS:V.A.G 1318 with adapter and Adapter Set:V.A.G 1318/10-12 in fuel line.

Fig 6: Connecting Fuel Inj. Pressure Gauge-CIS V.A.G 1318 With Adapter And Adapter Set V.A.G 1318/10-12 In Fuel Line

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-- Connect an assisting hose -arrow- to pressure gauge and hold it in a measuring container.

-- Open shut-off valve of pressure gauge.

The lever points in the flow direction.

-- Bleed fuel system by pressing remote control briefly.

-- Close shut-off valve of pressure gauge.

Lever stands perpendicular to direction of flow -arrow-.

Fig 7: Closing Pressure Gauge Cut-Off Valve
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-- Hold the switch of the remote control until no more pressure increase is observed on the fuel pressure gauge.

Specified value: approximately 5.5 bar (4.5 to 6.5 bar) positive pressure

If the specification is not obtained:

-- Check the fuel pump delivery quantity. Refer to DIAGNOSIS AND TESTING .