Ecd System Ecm Power Source Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK ECM (+B VOLTAGE)

CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

CHECK ECM (IGSW VOLTAGE)

CHECK ECM (MREL VOLTAGE)

CHECK NO. 1 INTEGRATION RELAY (EFI)

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (EFI) - ECM AND BODY GROUND)

INSPECT IGNITION SWITCH ASSEMBLY

ECD SYSTEM - ECM Power Source Circuit


DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to terminal IGSW of the ECM. The ECM "MREL" output signal causes current to flow to the EFI relay coil, closing the contacts of the EFI relay and supplying power to terminal +B of the ECM.

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.5L-E Engine Control.Ecd System.Ecd System Ecm Power Source Circuit


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.CHECK ECM (+B VOLTAGE)
Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.5L-E Engine Control.Ecd System.Ecd System Ecm Power Source Circuit

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    G183-1 (+B) - C161-5 (E1)
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Component with harness connected
    (ECM)


NG
Go to step 2
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (LandCruiser RM000000VQC00UX.html)

2.CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    C161-5 (E1) - Body ground
    		Always
    		Below 1 Ω

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK ECM (IGSW VOLTAGE)
Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.5L-E Engine Control.Ecd System.Ecd System Ecm Power Source Circuit

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    G183-11 (IGSW) - C161-5 (E1)
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Component with harness connected
    (ECM)


NG
Go to step 7
OK


4.CHECK ECM (MREL VOLTAGE)
Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.5L-E Engine Control.Ecd System.Ecd System Ecm Power Source Circuit

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    G186-10 (MREL) - C161-5 (E1)
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Component with harness connected
    (ECM)


NG
REPLACE ECM (LandCruiser RM000000VW203FX.html)
OK


5.CHECK NO. 1 INTEGRATION RELAY (EFI)
Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.5L-E Engine Control.Ecd System.Ecd System Ecm Power Source Circuit

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    1B-4 - Body ground
    		Ignition switch ON
    		10 to 14 V
    Text in Illustration
    *a
    		Rear view of wire harness connector
    (to No. 1 Integration Relay)

  1. Reconnect the No. 1 integration relay (EFI) connector.



NG
REPLACE NO. 1 INTEGRATION RELAY (EFI)
OK


6.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (EFI) - ECM AND BODY GROUND)

  1. Disconnect the No. 1 integration relay (EFI) connector from the engine room junction block.

  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
    1B-2 - G183-10 (MREL)
    		Always
    		Below 1 Ω
    1B-4 - G183-1 (+B)
    		Always
    		Below 1 Ω
    1B-3 - Body ground
    		Always
    		Below 1 Ω
    1B-2 or G183-10 (MREL) - Body ground
    		Always
    		10 kΩ or higher
    1B-4 or G183-1 (+B) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the No. 1 integration relay connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (TERMINAL +B OF ECM - BATTERY)

7.INSPECT IGNITION SWITCH ASSEMBLY

  1. Inspect the ignition switch assembly (LandCruiser RM000000YK004UX.html).



NG
REPLACE IGNITION SWITCH ASSEMBLY (LandCruiser RM000000YK103LX.html)
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - IGNITION SWITCH, IGNITION SWITCH - ECM)