Fuel Pump Control Circuit
1GR-FE ENGINE CONTROL SYSTEM: 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
INSPECTION PROCEDURE
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
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 fuel pump using the Techstream.
OK:
Operating sounds can be heard from fuel pump.
NG -- INSPECT CIRCUIT OPENING RELAY (C/OPN)
OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Check for Intermittent Problems
2. INSPECT CIRCUIT OPENING RELAY (C/OPN)
(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE CIRCUIT OPENING RELAY (C/OPN)
OK -- Continue to next step.
3. 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 - EFI RELAY, IGNITION SWITCH)
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - ECM, FUEL PUMP CONTROL ECU)
(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.
(b) Disconnect the ECM connector.
(c) Disconnect the fuel pump control ECU 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.
5. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP CONTROL ECU)
(a) Disconnect the fuel pump connector.
(b) Disconnect the fuel pump control 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.
6. INSPECT FUEL PUMP
(a) Inspect the fuel pump Fuel Pump.
NG -- REPLACE FUEL PUMP Removal
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU - ECM, BODY GROUND)
(a) Disconnect the fuel pump control 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.
8. REPLACE FUEL PUMP ECU
(a) Replace the fuel pump ECU Removal.
NEXT -- Continue to next step.
9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
(a) Check the fuel pump operation.
OK:
Malfunction has been repaired successfully.
NG -- REPLACE ECM Removal
OK -- END
10. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - EFI RELAY, IGNITION SWITCH)
(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.
(b) Remove the EFI relay (EFI) from the engine room relay block.
(c) Disconnect the ignition switch 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 -- GO TO ECM POWER SOURCE CIRCUIT ECM Power Source Circuit