Pinpoint Test C: Low Pressure Fuel Pump Tests

1. Remove the lower rear seat cushion. Refer to Rear Seat
2. Use an assistant to cycle the ignition status between On and Off to operate the low pressure pump. Ensure the engine remains off
3. Listen for a humming sound from the fuel pump for a couple of seconds

Can the fuel pump be heard running?

• Yes: GO to C4  .
• No: GO to C2  .

1. Locate the fuel pump fuse in the Rear Junction Box (RJB)
2. Check the fuel pump fuse

has the fuel pump fuse blown?

• Yes  : Refer to the electric circuit diagrams and check the fuel pump circuit for short circuit to power or short circuit to ground. Repair circuit as necessary. Install a new fuse and retest
• No: GO to C3  .

1. Using the manufacturer approved diagnostic system, find the datalogger signal for the fuel pump relay control button. Use this button to switch the fuel pump relay ON and OFF

Can the fuel pump relay be heard clicking each time it is turned ON and OFF

• Yes: GO to C4  .
• No  : Check the ampere rate of the relay. Check the fuel pump relay circuit for short circuit to ground. Repair as necessary and retest if the relay is not functioning, if the ampere rate of the relay is different replace it with a 70A relay

This test should be carried out by turning the ignition ON.

1. Connect the manufacturers approved battery support unit
2. Go back to the fuel pump
3. Use the manufacturer approved oscilloscope
4. Connect the oscilloscope to the low pressure fuel pump connector (C4MC11B)
5. Turn the ignition ON and record the outcome

Are the voltage values constantly oscillating between 0V and 13.5V in each of the phases as shown in the above figures?

• Yes  : GO to Pinpoint Test D .
• No: GO to C5  .

1. Disconnect the electrical connector on top of the fuel pump flange
2. Use the manufacturer approved oscilloscope
3. Check the resistance between terminal 1 and 2, 1 and 3, 2 and 3 of the low pressure fuel pump using an ohmmeter
4. Check if there is any evidence of frayed, melted wires/connectors or corroded connector pins

Is there any open or short circuit in the fuel pump connector or internal circuit? (Expected resistance value in the specified terminals is 0.5Ω)

• Yes  : Low pressure fuel pump internal failure. Install a new low pressure fuel pump. (310-01A: Fuel Tank and Lines - INGENIUM I4 2.0L Diesel/Removal and installation/Fuel Pump and sender unit)
• No: GO to C6. 

1. Reconnect the electrical connector on top of the fuel pump module flange
2. Locate the Fuel Pump Driver Module (FPDM)
3. Disconnect the electrical connector of the FPDM
4. Use the manufacturer approved ohmmeter
5. Check the resistance between terminal 1 and 2, 1 and 5, 2 and 5 of the FPDM harness side connector using an ohmmeter

Is there any open or short circuit in the wiring harness between FPDM and Low pressure fuel pump? (Expected resistance value in the specified terminals is 1Ω)

• Yes  : Repair the suspected wiring harness as required. (Refer to: Electrical Distribution
• No: GO to C7  .

1. Get a long wire lead that can reach the fuel pump and attach it to the -VE terminal of the battery
2. Use the manufacturers approved multimeter
3. Attach the -VE lead of the multimeter to the long wire lead which is attached to the battery --VE terminal
4. Attach the +VE lead of the multimeter to the -VE terminal of the Fuel Pump Driver module (FPDM) (Terminal 8)
5. Set the multimeter to VDC
6. Turn the ignition ON
7. Measure the voltage

Is the voltage drop >1V?

• Yes  : Check the ground connection of the FPDM and Repair as required. (Refer to: Electrical Distribution
• No: GO to C8. 

1. Get a long wire lead that can reach the Fuel pump Driver Module (FPDM) and attach it to the +VE terminal of the battery
2. Attach the +VE lead of the multimeter to the long wire lead which is attached to the battery
3. Attach the -VE terminal of the multimeter to the +VE terminal of the Fuel Pump Driver Module (FPDM) (Connector harness side: C1E528 terminal 4)
4. Set the multimeter to VDC
5. Turn the ignition ON
6. Measure the voltage

Is the voltage drop > 1V?

• Yes  : Check connector C31A, C31B (if fitted) and the wire between fuse box and FPDM, replace or repair them as necessary
• No  : GO to Pinpoint Test E .