Fuel Pump: Testing and Inspection

Fuel Pump Circuit Diagnostic Chart:

Fuel Pump Circuit:

DIAGNOSTIC CHART AND DIAGRAM
1. CHECK OPERATION OF FUEL PUMP IN D-CHECK MODE.
1) Connect test mode terminal.
2) Turn ignition switch to "ON".
3) Check fuel pump for proper operation.

Fuel Pump Relay:

2. CHECK FUEL PUMP RELAY.
1) Disconnect fuel pump relay connector, and remove fuel pump relay from bracket,
2) Measure resistance relay coil.

Connector & Terminal/Specified voltage
Fuel pump relay connector terminal:
No. 1 - No. 3/70 ohms

3) Connect battery (12 V) to fuel pump relay coil terminals, and check continuity between switching terminals. Relay must issue clicks.

Connector & Terminal/Specified voltage
Fuel pump relay connector terminal:
No. 2 - No. 4/0 ohms
(No. 1: Battery +)
(No. 3: Battery -)

3. CHECK POWER SUPPLY CIRCUIT OF FUEL PUMP RELAY.
1) Turn ignition switch to "OFF", and connect connector (B51) to fuel pump relay.
2) Turn ignition switch to "ON", and measure voltage between fuel pump relay and body.

Connector & Terminal/Specified voltage
(B51) No. 1 - Body/10 V, min.

4. CHECK INPUT SIGNAL FOR ECU.
1) Turn ignition switch to "ON".
2) Measure voltage between ECU connector (B47) and body.

Connector & Terminal/Specified voltage
(B82) No. 23 - Body/10 V, min.

3) Measure voltage at same terminal while cranking the engine.
Connector & Terminal/Specified voltage
(B62) No. 23 - Body/0 V

5. CHECK HARNESS CONNECTOR BETWEEN ECU AND FUEL PUMP RELAY.

1) Turn ignition switch to "OFF".
2) Disconnect ECU connector (B62) and fuel pump relay connector (B51).
3) Measure resistance of connector terminals between ECU and fuel pump relay.

Connector & Terminal/Specified voltage
(B62) No. 23 - (B51) No. 3/0 ohms

4) Measure resistance between fuel pump connector terminal and body to check short circuit.

Connector & Terminal/Specified voltage
(R23) No. 3 - Body / 1 ohm min.

Fuel Pump Connector:

6. CHECK VOLTAGE FOR FUEL PUMP.
1) Fold down the rear seat back, and turn up the floor mat.
2) Remove access hole lid.
3) Disconnect fuel pump connector (R23).
4) Measure voltage between connector (R23) and body while cranking the engine.


Connector & Terminal/Specified voltage
(R23) No. 1 - Body/10 V, min.


7. CHECK FUEL PUMP.
1) Connect battery (12 V) to proper fuel pump connector terminals to check fuel pump operation.
Terminal
No. 1 Battery +
No. 4 Battery -