Inspection Procedure 30: Fuel Pump System

OPERATION

The battery voltage is applied to the fuel pump relay (1) (terminal No. 1) form the ignition switch and is earthed to the vehicle body from the fuel pump relay (1) (terminal No. 2).
The battery voltage is applied to the fuel pump relay (1) (terminal No. 3) and to the fuel pump relay (2) (terminal No. 3) from the fuel pump relay (1) (terminal No. 4).
The battery voltage is applied to the fuel pump relay (2) (terminal No. 1) from the ignition switch. The engine-ECU (terminal No. 81) makes the power transistor in the unit be in "ON" position and makes currents go on the fuel pump relay (2) coil, and that makes the relay be in "ON" position.
When the fuel pump relay (2) is in "ON" position, the battery voltage is supplied to the fuel pump from the fuel pump relay (2) (terminal No. 4).

FUNCTIONS

When the ignition switch ON signal is input to the engine-ECU, the engine-ECU places the fuel pump relay in the "ON" position. Accordingly, the battery voltage is supplied to the fuel pump.

PROBABLE CAUSES

Failed fuel pump relay
Failed fuel pump
Open or shorted fuel pump drive circuit, harness damage, or connector damage
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-217 fuel pump relay (1) connector and B-203 fuel pump relay (2) connector

Q. Is the check result normal?

Go to Step 2 .

Repair or replace the connector.

STEP 2. Check fuel pump relay.

Fuel pump relay, continuity check (Refer to ).

Q. Is the check result normal?

	Go to Step 3 .

	Replace the fuel pump relay.

STEP 3. Perform resistance measurement at B-217 fuel pump relay (1) connector.

Remove relay, and measure at J/B side.
Resistance between terminal No. 2 and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 4 .

Check earthing line for open circuit and damage.

STEP 4. Perform voltage measurement at B-217 fuel pump relay (1) connector.

Remove relay, and measure at J/B side.
Ignition switch: ON
Voltage between terminal No. 1 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 6 .

Go to Step 5 .

STEP 5. Connector check: B-240 ignition switch connector

Q. Is the check result normal?

Check power supply line for open/short circuit and damage.

Repair or replace the connector.

STEP 6. Perform voltage measurement at B-217 fuel pump relay (1) connector.

Remove relay, and measure at J/B side.
Voltage between terminal No. 3 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 7 .

Check power supply line for open/short circuit.

STEP 7. Perform voltage measurement at B-203 fuel pump relay (2) connector.

Remove relay, and measure at J/B side.
Ignition switch: ON
Voltage between terminal No. 1 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 9 .

Go to Step 8 .

STEP 8. Connector check: B-240 ignition switch connector

Q. Is the check result normal?

Check power supply line for open circuit.

Repair or replace the connector.

STEP 9. Connector check: A-09 engine-ECU connector.

Q. Is the check result normal?

Go to Step 10 .

Repair or replace the connector.

STEP 10. Perform voltage measurement at A-09 engine-ECU connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 81 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 11 .

Check earthing line for open/short circuit.

STEP 11. Connector check: C-13 fuel pump connector

Q. Is the check result normal?

Go to Step 12 .

Repair or replace the connector.

STEP 12. Perform voltage measurement at C-13 fuel pump connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Using a jumper wire, connect A-09 (terminal No. 81) engine-ECU connector and earth.
Voltage between terminal No. 2 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 15 .

Go to Step 13 .

STEP 13. Check harness between B-217 (terminal No. 4) fuel pump relay (1) connector and B-203 (terminal No. 3) fuel pump relay (2) connector.

Check power supply line for open/short circuit.

Q. Is the check result normal?

Go to Step 14

Repair the damaged harness wire.

STEP 14. Check harness between B-203 (terminal No. 4) fuel pump relay (2) connector and C-13 (terminal No. 2) fuel pump connector.

note

Before checking harness, check intermediate connector B-228, and repair if necessary.

Check power supply line for open/short circuit and damage.

Q. Is the check result normal?

Replace the engine-ECU then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding

Repair the damaged harness wire.

STEP 15. Perform resistance measurement at C-13 fuel pump connector.

Disconnect connector, and measure at harness side.
Resistance between terminal No. 3 and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 16 .

Check earthing line for open circuit and damage.

STEP 16. Connector check: B-240 ignition switch connector

Q. Is the check result normal?

Go to Step 17 .

Repair or replace the connector.

STEP 17. Check harness between B-240 (terminal No. 2) ignition switch connector and B-217 (terminal No. 1) fuel pump relay (1) connector.

note

Before checking harness, check intermediate connector B-229, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 18 .

Repair the damaged harness wire.

STEP 18. Check harness between battery and B-217 (terminal No. 3) fuel pump relay (1) connector.

note

Before checking harness, check intermediate connector B-208, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 19 .

Repair the damaged harness wire.

STEP 19. Check harness between B-217 (terminal No. 4) fuel pump relay (1) connector and B-203 (terminal No. 3) fuel pump relay (2) connector.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 20 .

Repair the damaged harness wire.

STEP 20. Check harness between B-240 (terminal No. 2) ignition switch connector and B-203 (terminal No. 1) fuel pump relay (2) connector.

note

Before checking harness, check intermediate connectors B-229, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 21 .

Repair the damaged harness wire.

STEP 21. Check harness between B-203 (terminal No. 4) fuel pump relay (2) connector and C-13 (terminal No. 2) fuel pump connector.

note

Before checking harness, check intermediate connectors B-228, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 22 .

Repair the damaged harness wire.

STEP 22. Check harness between B-203 (terminal No. 2) fuel pump relay (2) connector and A-09 (terminal No. 81) engine-ECU connector.

note

Before checking harness, check intermediate connector B-210, and repair if necessary.

Check earthing line for damage.

Q. Is the check result normal?

Replace the fuel pump.

Repair the damaged harness wire.