SFI SYSTEM > Fuel Pump Control Circuit

for Preparation Click here


DESCRIPTION

When the engine is cranked, the start request signal output from the power management control ECU *1, or ignition or starter switch assembly*2 is input to the ECM, and the NE signal generated by the crank position sensor is also input to the NE+ terminal. Thus, the ECM interprets that the engine has been cranked, and turns transistor Tr1 in the ECM internal circuit on. Current flows to the C/OPN (Circuit Opening) relay by turning Tr1 on. Then, the fuel pump with filter assembly operates.
While the NE signal is input to the ECM with the engine running, the ECM turns Tr1 on continuously.
  1. *1: w/ Smart Key System
  2. *2: w/o Smart Key System

WIRING DIAGRAM


A275615E01


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP / SPEED)
  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON (IG).

  1. Turn the Techstream on.

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

  1. Check whether the fuel pump with filter assembly operating sound occurs when performing the Active Test on the Techstream.

    Result 
    Result
    Proceed to
    Fuel pump with filter assembly operating sound does not occur
    A
    Fuel pump with filter assembly operating sound occurs
    B


B
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)
A


2.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)
  1. Remove the No. 1 integration relay from the No. 2 engine room relay block and No. 2 junction block assembly.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    Condition
    Specified Condition
    2D-4 - A40-21 (FC)
    Always
    Below 1 Ω
    2D-4 or A40-21 (FC) - Body ground
    Always
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - FUEL PUMP WITH FILTER ASSEMBLY)
  1. Remove the No. 1 integration relay from the No. 2 engine room relay block and No. 2 junction block assembly.

  1. Disconnect the fuel pump with filter assembly connector.

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

    Standard Resistance:

    Tester Connection
    Condition
    Specified Condition
    2D-8 - M22-4 (B)
    Always
    Below 1 Ω
    2D-8 or M22-4 (B) - Body ground
    Always
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (FUEL PUMP WITH FILTER ASSEMBLY - BODY GROUND)
  1. Disconnect the fuel pump with filter assembly connector.

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

    Standard Resistance:

    Tester Connection
    Condition
    Specified Condition
    M22-5 (E) - Body ground
    Always
    Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.INSPECT FUEL PUMP WITH FILTER ASSEMBLY
  1. Inspect the fuel pump with filter assembly (Click here).

    HINT:
    Perform "Inspection After Repair" after replacing the fuel pump with filter assembly (Click here).


NG
REPLACE FUEL PUMP WITH FILTER ASSEMBLY (Click here)
OK


6.INSPECT NO. 1 INTEGRATION RELAY (C/OPN RELAY)
  1. Inspect the No. 1 integration relay (C/OPN relay) (Click here).



NG
REPLACE NO. 1 INTEGRATION RELAY (Click here)
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY - NO. 1 INTEGRATION RELAY)