Fuel Pump Control Circuit

2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: Fuel Pump Control Circuit
- Fuel Pump Control Circuit

DESCRIPTION

The FUEL PUMP relay switches the fuel pump speed according to the engine conditions. The fuel pump operates when the ECM receives the starter-operating signal (STA) and crankshaft-rotating signal (NE).

The FUEL PUMP relay is turned ON while the engine is idling or operating at low load. This causes current to flow through the fuel pump resistor to the fuel pump. The fuel pump then operates at low speed.

The FUEL PUMP relay is turned OFF while the engine is cranking or operating at high load. The fuel pump then operates at normal speed.





WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE C/OPN RELAY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch on (IG), and turn the tester on.

(c) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.

(d) Check the relay operation while operating it using the tester.

Standard:

Operating noise can be heard from the relay.

NG -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
OK -- Continue to next step.

2. INSPECT TERMINAL VOLTAGE (FUEL PMP RELAY TERMINAL)

(a) Remove the FUEL PMP relay from the engine room relay block.





(b) Turn the ignition switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard voltage:





Text in Illustration





(d) Reinstall the FUEL PMP relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL PMP RELAY - C/OPN RELAY)
OK -- Continue to next step.

3. INSPECT RELAY (FUEL PMP RELAY)

(a) Remove the FUEL PMP relay from the engine room relay block.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





(c) Reinstall the FUEL PMP relay.

NG -- REPLACE RELAY (FUEL PMP RELAY)
OK -- Continue to next step.

4. INSPECT FUEL PUMP RESISTOR

(a) Disconnect the fuel pump resistor connector.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





Text in Illustration





(c) Reconnect the fuel pump resistor connector.

NG -- REPLACE FUEL PUMP RESISTOR Components
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PMP RELAY)

(a) Check the wire harness between the FUEL PMP relay and fuel pump.

(1) Remove the fuel pump relay from the engine room relay block.

(2) Disconnect the fuel pump connector.

(3) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY - FUEL PUMP RESISTOR)

(a) Disconnect the fuel pump resistor connector.

(b) Remove the fuel pump relay from the engine room relay block.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the fuel pump resistor connector.

(e) Reinstall the fuel pump relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (FUEL PUMP RESISTOR - FUEL PUMP)

(a) Disconnect the fuel pump resistor connector.

(b) Disconnect the fuel pump connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the fuel pump resistor connector.

(e) Reconnect the fuel pump connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

8. INSPECT FUEL PUMP

(a) Inspect the fuel pump.





(1) Measure the resistance according to the value(s) in the table below.

Standard resistance:





Text in Illustration





(2) Apply battery voltage to both terminals 4(+) and 5(-). Check that the pump operates.

NOTICE:
* These tests must be done quickly (within 10 seconds) to prevent the coil from burning out.
* Keep the fuel pump as far away from the battery as possible.
* Always turn ON and OFF the voltage on the battery side, not on the fuel pump side.

NG -- REPLACE FUEL PUMP ASSEMBLY Components

OK -- CHECK AND REPLACE FUEL FILTER

9. CHECK ECM POWER SOURCE CIRCUIT

HINT
.

NG -- REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT
OK -- Continue to next step.

10. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (C/OPN RELAY)

(a) Inspect the C/OPN relay Testing and Inspection.

NG -- REPLACE CIRCUIT OPENING RELAY Components
OK -- Continue to next step.

11. INSPECT ECM (FC VOLTAGE)

(a) Turn the ignition switch on (IG).





(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (ECM - C/OPN RELAY)

OK -- REPLACE ECM Components

12. CHECK HARNESS AND CONNECTOR (ECM - C/OPN RELAY)

(a) Disconnect the ECM connector.

(b) Remove the engine room junction block.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the ECM connector.

(e) Reinstall the engine room junction block.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - C/OPN RELAY)

OK -- REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY Components