DESCRIPTIONThe fuel pump (for low pressure side) circuit consists of the ECM, fuel pump (for low pressure side) and fuel pump control ECU (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. Based on the signal sent from the ECM, the fuel pump control ECU adjusts the fuel pump (for low pressure side) operation speed. WIRING DIAGRAMCAUTION / NOTICE / HINTNOTICE: Inspect the fuses for circuits related to this system before performing the following procedure. PROCEDURE
(a) Check around and beneath the vehicle for fuel leaks, fumes, etc. OK: No fuel leaks present.
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON. (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay. Powertrain > Engine > Active Test
(e) Check whether the fuel pump operating sound occurs when performing the Active Test on the Techstream. Standard:
(a) Install the fuel pressure gauge (for low pressure line of low pressure side). (b) Connect the Techstream to the DLC3. (c) Turn the ignition switch to ON. (d) Turn the Techstream on. (e) Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty Ratio / Data List / Fuel Pressure (Low) / Fuel Pressure 2. Powertrain > Engine > Active Test
(f) Compare the values in the Data List using the Techstream and the fuel pressure gauge when the Active Test was performed. Standard:
HINT: Perform "Inspection After Repair" after replacing the fuel pressure sensor (for low pressure side).
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON. (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Data List / Target Fuel Pressure (Low) / Target Fuel Pressure 2, Fuel Pressure (Low) / Fuel Pressure 2 and Low Fuel Pressure Sensor. Powertrain > Engine > Data List
(e) Read the values displayed on the Techstream while the engine is cranking.
HINT: Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).
(a) Install the fuel pressure gauge (for low pressure line of low pressure side). (b) Start the engine. (c) Measure the fuel pressure at idle. Standard Fuel Pressure: 300 to 530 kPa (3.1 to 5.4 kgf/cm2, 44 to 77 psi) HINT: Refer to Standard Idle Speed. (d) Stop the engine. (e) Check that the fuel pressure remains as specified for 5 minutes. Standard Fuel Pressure: 98 kPa (1.0 kgf/cm2, 14.2 psi) or more HINT: Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).
(a) Check the amount of fuel remaining. HINT:
(a) Disconnect the fuel pump (for low pressure side) connector. (b) Connect the Techstream to the DLC3. (c) Turn the ignition switch to ON. (d) Turn the Techstream on. (e) Enter the following menus: Powertrain / Engine / Active Test / Fuel Pump Single Phase Energization. Powertrain > Engine > Active Test
(f) Operate the fuel pump control ECU using the Active Test function and measure the voltage according to the value(s) in the table below. Standard Voltage:
HINT:
(a) Disconnect the fuel pump (for low pressure side) connector. (b) Disconnect the fuel pump control ECU connector. (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
(a) Disconnect the fuel pump control ECU connector. (b) Turn the ignition switch to ON. (c) Measure the voltage according to the value(s) in the table below. Standard Voltage:
(a) Disconnect the fuel pump control ECU connector. (b) Connect the Techstream to the DLC3. (c) Turn the ignition switch to ON. (d) Turn the Techstream on. (e) Enter the following menus: Powertrain / Engine / Active Test / Fuel Pump Single Phase Energization. Powertrain > Engine > Active Test
(f) Operate the fuel pump control ECU using the Active Test function and measure the resistance according to the value(s) in the table below. Standard Resistance:
HINT: *: 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.
(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:
(a) Disconnect the fuel pump control ECU connector. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and junction block assembly. (b) Measure the voltage according to the value(s) in the table below. Standard Voltage:
(a) Inspect the EFI-MAIN NO. 2 relay.
(a) Remove the EFI-MAIN NO. 1, EFI-MAIN NO. 2, VVT and A/F HTR relays from the No. 1 engine room relay block and junction block assembly. HINT: Remove the VVT and A/F HTR relays connected between the checked terminals as the coil inside the relay influences the measurement value. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and junction block assembly. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and junction block assembly. (b) Disconnect the fuel pump control ECU connector. (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
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