DESCRIPTION
The fuel pump (for low pressure side) circuit consists of the ECM, fuel pump (for low pressure side) and fuel pump control ECU assembly (which operates the fuel pump (for low pressure side)). 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 control ECU assembly. Based on the signal sent from the ECM, the fuel pump control ECU assembly adjusts the fuel pump (for low pressure side) operation speed.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
INSPECT FUEL PUMP CONTROL ECU ASSEMBLY
*1 | Fuel Pump Control ECU Assembly | - | - |
Remove the fuel pump control ECU assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||||||||||||||
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Tech Tips
This procedure checks for an internal short of the fuel pump control ECU assembly when its transistor is stuck on.
Result | |||
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|
NG |
REPLACE FUEL PUMP CONTROL ECU ASSEMBLY Click here |
OK |
CHECK HARNESS AND CONNECTOR (POWER SOURCE OF FUEL PUMP CONTROL ECU ASSEMBLY)
*a | Front view of wire harness connector (to Fuel Pump Control ECU Assembly) |
Disconnect the fuel pump control ECU assembly connector.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||
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|
Tech Tips
Make a note of the measured voltage as it may be used in a following Active Test.
Result | |||
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|
NG |
CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF FUEL PMP RELAY) Click here |
OK |
CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - ECM)
Disconnect the fuel pump control ECU assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
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Result | |||
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NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
PERFORM ACTIVE TEST USING GTS (FUEL PUMP SINGLE PHASE ENERGIZATION)
*1 | Fuel Pump Control ECU Assembly | - | - |
Disconnect the S48 fuel pump control ECU assembly connector.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Active Test / Fuel Pump Single Phase Energization.
Tester Display |
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Fuel Pump Single Phase Energization |
Operate the fuel pump control ECU assembly using the Active Test function and measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||||||||
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|
Tech Tips
*: This Active Test restricts the fuel pump control ECU assembly output duty cycle to 50%. Therefore, the output voltage of the fuel pump control ECU assembly will be approximately 50% of the power source voltage measured in a previous step.
Before performing this inspection, check that the battery voltage is between 11 and 14 V (not depleted).
Result | ||||||||
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|
B |
REPLACE FUEL PUMP CONTROL ECU ASSEMBLY Click here |
C |
INSPECT ECM (FPC TERMINAL) Click here |
A |
CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - FUEL PUMP (FOR LOW PRESSURE SIDE))
Disconnect the fuel pump control ECU assembly connector.
Disconnect the fuel pump (for low pressure side) connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Result | |||
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|
Tech Tips
Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).
OK |
REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT ECM (FPC TERMINAL)
*a | Front view of wire harness connector (to Fuel Pump Control ECU Assembly) |
Disconnect the fuel pump control ECU assembly connector.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Active Test / Fuel Pump Single Phase Energization.
Tester Display |
---|
Fuel Pump Single Phase Energization |
Operate the fuel pump control ECU assembly using the Active Test function and measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
Tech Tips
*: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the FPC terminal will be unstable during the Active Test. If the resistance is stable before the Active Test and fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.
Result | |||
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|
OK |
REPLACE FUEL PUMP CONTROL ECU ASSEMBLY Click here |
NG |
REPLACE ECM Click here |
CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF FUEL PMP RELAY)
Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||
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Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FUEL PMP RELAY) |
OK |
INSPECT FUEL PMP RELAY
Inspect the FUEL PMP relay.
Result | |||
---|---|---|---|
|
NG |
REPLACE FUEL PMP RELAY |
OK |
CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - ECM)
Disconnect the semiconductor pwr integration ECU connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
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Result | |||
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NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - FUEL PMP RELAY)
Disconnect the semiconductor pwr integration ECU connector.
Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
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Result | |||
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NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (FUEL PMP RELAY - BODY GROUND)
Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
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|
Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (FUEL PMP RELAY - FUEL PUMP CONTROL ECU ASSEMBLY)
Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Disconnect the fuel pump control ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
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Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - BODY GROUND)
Disconnect the fuel pump control ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
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Result | |||
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OK |
GO TO ECM POWER SOURCE CIRCUIT Click here |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |