Fuel Pump: Testing and Inspection

Checking Fuel Pump Delivery Pressure (S54)

Special tools required:
- 13 5 220
- 13 5 221
- 13 5 222
- 61 3 050

Switch off ignition.


CAUTION:
The fuel in the fuel lines is under pressure (approx. 5 bar)!
Catch and dispose of escaping fuel.







Release screw connections (1).
Remove cover (2) on floor plate on left.







Installation Note: Ensure seal (1)is in correct installation position.







Remove dust cap (1).







Connect special tool kit 13 5 220 (comprising 13 5 221 and 13 5 222 ) to pressure sensor of DIS Tester.
Connect pressure sensor to DIS Tester.


CAUTION: Do not under any circumstances screw in the check valve up to the mechanical stop. This could damage the valve in the pressure regulator housing.







Attach special tool kit 13 5 220 to housing of pressure regulator and tighten knurled nut until hand-tight. Screw out check valve (1) 50 that valve in pressure regulator housing is closed.
Start engine.
Screw in check valve (1) until a pressure reading is indicated on DIS Tester.

Measuring fuel pressure.
- Select Measurement.
- Multimeter function appears
- Select Pressure test
- Read off value of fuel pressure.
Compare actual value of test pressure with specified value.
Switch off engine.

Checking fuel pump:
Remove fuel pump relay.







Connect special tool 61 3 050 to terminals 87 and 30.
Press button and read off fuel pump delivery pressure on DIS Tester.
Compare actual value with setpoint value of delivery pressure.



NOTE:
Removing special tool kit 13 5 220
- Switch off engine
- Screw out check valve fully again.
- Remove special tool kit 13 5 220 from pressure regulator housing.
- Catch and dispose of escaping fuel.


NOTE:
Interrogate fault memory of DME control unit.
Check stored fault messages.
Rectify faults.
Then clear fault memory.