Checking the Fuel Pump

Fuel Pump
- Ignition OFF.
- Remove fuse 1 (11B/1) in integrated relay/fusebox.
- Ignition ON.
- Lightly squeeze the hose connected to the fuel pressure regulator and reinstall fuse.
- Check that the fuel pump (FP) works for a few seconds after the fuse is refitted. When the fuel pump is operating the fuel hose pulses.

NOTE: If the pump does not work at the first attempt, repeat the process a couple of times to verify that the pump does not work.

- Does the fuel pump work?

Yes:
^ Proceed to: Checking Ignition Spark.

No:
^ Proceed to: Starting Fuel Pump section below.





Starting Fuel Pump
- Ignition OFF.
- Remove fuel pump relay (2/23) position 2 in the integrated relay/fusebox on the left of the dashboard.
- Connect jumper cable across relay base terminals 1 and 3.
- Ignition ON.
- Lightly squeeze the hose connected to the fuel pressure regulator and reinstall fuse.
- Check that the fuel pump works. When the fuel pump is operating the fuel hose pulses.
- Does the fuel pump work?

Yes:
^ Proceed to: Checking Fuel Pump Relay Signal Cable section below.

No:
^ Proceed to: Checking the Voltage Supply to the Relay section below.





Checking the Voltage Supply to the Relay
- Ignition OFF.
- Fuel pump relay removed.
- Ignition ON.
- Connect a voltmeter between relay base terminal 1 and ground.
- The voltmeter should read battery voltage.

If reading is OK:
^ Proceed to: Checking Fuel Pump Ground Lead section below.

If reading is incorrect:
^ Proceed to: Checking Fuse 4 section below.





Checking Fuse 4
- Check that fuse 4 (11B/4) is intact.
- Is the fuse intact?

Yes:
^ Proceed to: Checking Voltage to Fuse 4 section below.

No:
^ Check circuit after fuse for a short-circuit to ground.





Checking Voltage to Fuse 4
- Ignition ON.
- Fuel pump relay removed.
- Connect a voltmeter between the rear socket on the fuse holder for fuse 4 (11B/4) and ground.
- The voltmeter should read battery voltage.

If reading is OK:
^ Check cable between fuse 4 and fuel pump relay terminal 1 for an open-circuit.

If reading is incorrect:
^ Check cable between main relay terminal 3 and fuse 4 for an open-circuit.





Checking Fuel Pump Ground Lead
- Ignition OFF.
- Disconnect 4-pin fuel pump connector in the cargo compartment.
- Connect an ohmmeter between fuel pump connector terminal 4 (fuel pump relay side) and ground.
- The ohmmeter should read approx. 0 ohms.

If reading is OK:
^ Proceed to: Checking the Fuel Pump section below.

If reading is incorrect:
^ Proceed to: Checking Fuel Pump Ground Terminal section below.





Checking Fuel Pump Ground Terminal
- Ignition OFF.
- Fuel pump disconnected.
- Check fuel pump ground terminal (31/66) by the left seat support for contact resistance and oxidation and remedy.
- Connect an ohmmeter between fuel pump connector terminal 4 (fuel pump relay side) and ground.
- The ohmmeter should read approx. 0 ohms.

If reading is OK:
^ The cause of the fault has been loose connections in the fuel pump ground terminal.

If reading is incorrect:
^ Check the cable between fuel pump connector terminal 4 and ground terminal (31/66) by the left seat support for an open-circuit.





Checking the Fuel Pump
- Ignition OFF.
- Fuel pump disconnected.
- Connect an ohmmeter between fuel pump connector terminals 1 and 4 (fuel pump side).
- Instrument should indicate approx. 0.5 - 2 ohms.

If reading is OK:
^ Check cable between fuel pump relay terminal 3 and fuel pump terminal 1 for an open-circuit.

If reading is incorrect:
^ Try a new fuel pump.





Checking Fuel Pump Relay Signal Cable
- Ignition ON.
- Fuel pump relay removed.
- Connect a voltmeter between relay base terminal 4 and ground.
- The voltmeter should read approx. 5 - 6 Volts.

If reading is OK:
^ Proceed to: Checking Connector section below.

If value is higher:
^ Check cable between fuel pump relay terminal 4 and engine control module (ECM) # B19 for a short- circuit to supply voltage.

If value is lower:
^ Proceed to: Checking Signal Cable Resistance to Ground section below.





Checking Signal Cable Resistance to Ground
- Ignition OFF.
- Fuel pump relay removed.
- Connect an ohmmeter between relay base terminal 4 and ground.
- The ohmmeter should read infinite resistance.

If reading is OK:
^ Check cable between fuel pump relay terminal 4 and engine control module (ECM) #B19 for an open- circuit.
^ Proceed to: Checking Connector section below.

If reading is incorrect:
^ Check cable between fuel pump relay terminal 4 and engine control module # B19 for a short- circuit to ground.





Checking Connector
- Ignition OFF.
- Reinstall fuel pump relay.
- Connect fuel pump.
- Try to start the engine.
- Does the engine start?

Yes:
^ The cause of the fault has been loose connections in the fuel pump relay or fuel pump connectors.
^ Check connectors for contact resistance and oxidation and remedy.

No:
^ Try a new fuel pump relay.