Ecd System Fuel Pump Control Circuit

Engine. Lexus Is250, Is220D. Gse20 Ale20
2Ad-Fhv Engine Control System. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FUEL GAUGE OPERATION (FUEL PUMP OPERATION)

PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE F/PMP RELAY)

PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE F/PMP RELAY)

INSPECT F/PMP RELAY

CHECK HARNESS AND CONNECTOR (F/PMP RELAY - FUEL PUMP RESISTER)

INSPECT FUEL PUMP

CHECK TERMINAL VOLTAGE

CHECK HARNESS AND CONNECTOR (FUEL PUMP - F/PMP RELAY)

ECD SYSTEM - Fuel Pump Control Circuit


DESCRIPTION

A fuel pump is located in the fuel tank and controlled by the ECM. The fuel pump operates only when fuel transfer operation and priming operation are performed.
Fuel transfer operation:
When the fuel level in fuel tank chamber A decreases, the ECM activates the fuel pump to transfer the fuel from chamber B to chamber A to keep the fuel level in chamber A above the specified level.
Priming operation:
The ECM turns on the three-way valve, changing the route of the fuel. Then the fuel pump is operated by the ECM in order to send the fuel from the fuel pump to the fuel supply pump in order to bleed air from the supply pump and fuel inlet pipe.

Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Fuel Pump Control Circuit


WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Fuel Pump Control Circuit


INSPECTION PROCEDURE

1.CHECK FUEL GAUGE OPERATION (FUEL PUMP OPERATION)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch ON (IG) and turn the tester ON.

  1. Enter the following menus: Body / Combination Meter / Data List / Fuel Input and Sub Fuel Gauge.

  1. Read the value.

    NG:
    Fuel Input:
    158 or more
    Sub Fuel Gauge:
    123 or less


NG
REPAIR OR REPLACE FUEL RECEIVER GAUGE
OK


2.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE F/PMP RELAY)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch ON (IG) and turn the intelligent tester ON.

  1. Enter the following menus: Power train / Engine / Active Test / Activate the Intank Fuel Pump Relay.

  1. Check the operation of the fuel pump while operating it using the intelligent tester.

    OK:
    Operating noise can be heard from the pump.


OK
CHECK AND REPLACE FUEL PIPE
NG


3.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (OPERATE F/PMP RELAY)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester ON.

  1. Enter the following menus: Power train / Engine / Active Test / Activate the Intank Fuel Pump Relay.

  1. Check the operation of the F/PMP relay while operating it using the intelligent tester.

    OK:
    Operating noise can be heard from F/PMP Relay.


OK
Go to step 6
NG


4.INSPECT F/PMP RELAY


    Lexus Is250, Is220D. Gse20 Ale20

  1. Remove the F/PMP relay from the engine room J/B and R/B No. 2.

  1. Measure the resistance of the F/PMP relay.

    Standard resistance:
    Tester Connection
    		Specified Condition
    3 - 5
    		10 kΩ or higher
    3 - 5
    		Below 1 Ω
    (when battery voltage applied to terminals 1 and 2)


NG
REPLACE F/PMP RELAY
OK


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


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Fuel Pump Control Circuit

  1. Remove the F/PMP relay and EFI MAIN relay from the engine room J/B and R/B No. 2.

  1. Disconnect the E59 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    F/PMP relay (1) - EFI MAIN relay (3)
    		Below 1 Ω
    F/PMP relay (2) - FC (E59-83)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    Fuel pump relay (1) - Body ground
    		10 kΩ or higher
    Fuel pump relay (2) - Body ground
    		10 kΩ or higher

  1. Reinstall the F/PMP relay and EFI MAIN relay.

  1. Reconnect the ECM connector.



OK
REPLACE ECM
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.INSPECT FUEL PUMP


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Fuel Pump Control Circuit

  1. Inspect fuel pump resistance.

    1. Measure the resistance between terminals 4 and 5.

      Standard resistance:
      0.2 to 3.0 Ω at 20°C (68°F)

  1. Inspect fuel pump operation.

    1. Apply battery voltage to both the terminals. Check that the pump operates.

      NOTICE:
      1. These tests must be done quickly (within 10 seconds) to prevent the coil from burning out.
      2. Keep the fuel pump as far away from the battery as possible.
      3. Always switch at the battery side.


NG
REPLACE FUEL PUMP
OK


7.CHECK TERMINAL VOLTAGE


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Fuel Pump Control Circuit

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch ON (IG) and turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / Active Test / Activate the Intank Fuel Pump Relay.

  1. Measure the voltage of the fuel pump connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    Q14-4 - Q14-5
    		Relay ON
    		9 to 14 V


OK
REPLACE FUEL PUMP
NG


8.CHECK HARNESS AND CONNECTOR (FUEL PUMP - F/PMP RELAY)


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System.Ecd System Fuel Pump Control Circuit

  1. Check the harness and the connectors between the fuel pump and the F/PMP relay.

    1. Disconnect the fuel pump connector.

    2. Remove the F/PMP relay from the engine room J/B and R/B No. 2.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open):
      Tester Connection
      		Specified Condition
      Fuel pump (Q14-4) - F/PMP relay (3)
      		Below 1 Ω
      Standard resistance (Check for short):
      Tester Connection
      		Specified Condition
      Fuel pump (Q14-4) or F/PMP (3) - Body ground
      		10 kΩ or higher

  1. Check the harness and the connectors between the fuel pump and the body ground.

    1. Disconnect the fuel pump connector.

    2. Measure the resistance of the wire harness side connector and the body ground.

      Standard resistance (Check for open):
      Tester Connection
      		Specified Condition
      Fuel pump (Q45-5) - Body ground
      		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL PUMP - BODY GROUND)
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (F/PMP RELAY - FUEL PUMP)