Fuel Delivery, Checking

Fuel Delivery, Checking

Special tools, testers and auxiliary items required

• Hand held remote control (jumper).

• Multimeter.

• Electrical connector test lead set.

• Measuring container, fuel-resistant.

Test conditions

• Battery voltage 12.5 V

• Fuel filter OK

• Fuel tank at least 1/4 filled.

• Fuel pressure regulator OK.

• Fuel Pump (FP) Control Module (-J538-) OK

• Ignition switched off.

Test procedure

- Perform a preliminary check to verify the customer's complaint. Refer to => [ Preliminary Check ] Preliminary Check

- Remove rear seat bench.





- Remove bolts - arrows - and remove cover for right locking flange.





- Disconnect the electrical connector - arrow - at locking flange.

- Connect a hand held remote control (jumper) using an adapter cable from the connector test set to contact 5.

- Using insulating tape, tape over second contact of the remote control (jumper) to prevent a short circuit.

- Route switch of the remote control (jumper) forward into the engine compartment.

- Connect alligator clip to ground (GND) point in engine compartment.

- Connect contact 1 to battery positive terminal (B+) using a self-made jumper cable. For safety reasons, install a 10 A fuse in the wiring.

- Remove fuel filler cap from fuel filler tube.





- Pull rear engine cover off - arrows -.

- Pull resonator upward and unclip it.

CAUTION!
Fuel system is under pressure! Before opening system, place rags around the connection area. Then release pressure by carefully loosening the connection.

- Disconnect fuel line - arrow -.





- Connect a pressure gauge adapter to the fuel line using the necessary adapters.

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

- Open shut-off valve of pressure gauge. Lever points in direction of flow.

- Generate pressure in fuel system by pressing switch of remote control and slowly closing shut-off valve of pressure gauge.

• Specification: 4 bar positive pressure.

• From this point on do not move position of shut-off tap.

- Empty measuring container.

- Press switch on remote control for 15 Sec.

- Compare quantity of fuel delivered with minimum delivery rate in diagram (cm3/15s).





• Voltage at fuel pump with engine stopped and pump running is approx. 2 V less than battery voltage.

If minimum delivery quantity is not obtained, the following malfunctions may be present:

• Fuel lines pinched

• Fuel filter clogged

• Fuel pump faulty

- Assembly is performed in the reverse of the removal.

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.