Fuel Pump Control Circuit

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

DESCRIPTION

The fuel pump circuit consists of the ECM, fuel pump and fuel pump ECU (which operates the fuel pump). Based on the engine output, the ECM determines the fuel pump speed. The speed is then converted to a duty signal and sent to the fuel pump ECU. Based on the signal sent from the ECM, the fuel pump ECU adjusts the fuel pump operation speed between 3 settings.

WIRING DIAGRAM

Proceed to P0230 P0230.

INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

This troubleshooting procedure is based on the premise that the engine is started. If the engine is not started, proceed to the problem symptoms table Symptom Related Diagnostic Procedures.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (FUEL PUMP)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream ON.

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

(d) Check whether operating sounds can be heard while operating the relay using the Techstream.

OK:

Operating sounds can be heard from relay.

NG -- INSPECT CIRCUIT OPENING RELAY (C/OPN)
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)

(a) Disconnect the fuel pump ECU connector.

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





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

3. REPLACE FUEL PUMP ECU

(a) Replace the fuel pump ECU Removal.

(b) Check the fuel pump operation.

OK:

Malfunction has been repaired successfully.

NG -- REPLACE ECM Removal

OK -- END

4. INSPECT CIRCUIT OPENING RELAY (C/OPN)

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

NG -- REPLACE CIRCUIT OPENING RELAY (C/OPN)
OK -- Continue to next step.

5. INSPECT CIRCUIT OPENING RELAY (POWER SOURCE VOLTAGE)





(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.

(b) Turn the ignition switch to ON.

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

Standard Voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - IGN FUSE, INTEGRATION RELAY)
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - ECU, FUEL PUMP ECU)

(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.

(b) Disconnect the fuel pump ECU connector.

(c) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





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

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

(a) Disconnect the fuel pump connector.

(b) Disconnect the fuel pump ECU connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





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

8. INSPECT FUEL PUMP

(a) Inspect the fuel pump Fuel Pump.

NG -- REPLACE FUEL PUMP Removal
OK -- Continue to next step.

9. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)

(a) Disconnect the fuel pump ECU connector.

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





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

10. REPLACE FUEL PUMP ECU

(a) Replace the fuel pump ECU Removal.

(b) Check the fuel pump operation.

OK:

Malfunction has been repaired successfully.

NG -- REPLACE ECM Removal

OK -- END

11. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - IGN FUSE, INTEGRATION RELAY)

(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.

(b) Remove the IGN fuse from the engine room relay block.

(c) Remove the integration relay from the engine room junction block.

(d) Disconnect the integration relay connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- GO TO ECM POWER SOURCE CIRCUIT Component Tests and General Diagnostics