ECM Power Source Circuit 1GR-FE

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BATTERY)

INSPECT INTEGRATION RELAY (EFI RELAY AND IG2 RELAY)

CHECK HARNESS AND CONNECTOR (+B, +B2 AND MREL CIRCUIT)

CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

INSPECT ECM (IGSW VOLTAGE)

INSPECT FUSE (IGN)

CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, INTEGRATION RELAY - BODY GROUND)

CHECK IF VEHICLE IS EQUIPPED WITH ENTRY AND START SYSTEM

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ENGINE ROOM RELAY BLOCK)

CHECK ENTRY AND START SYSTEM (POWER SOURCE MODE DOES NOT CHANGE)

CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - ENGINE ROOM RELAY BLOCK)

INSPECT IGNITION SWITCH ASSEMBLY

SFI system - ECM Power Source Circuit

Description

When the ignition switch is turned to ON, battery voltage is applied to the IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the integration relay (EFI relay) and supplying power to either terminal +B or +B2 of the ECM.

Wiring diagram

Inspection procedure

1.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BATTERY)

1. Remove the integration relay from the engine room relay block.

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

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   1C-1 - Body ground	Always	11 to 14 V

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.INSPECT INTEGRATION RELAY (EFI RELAY AND IG2 RELAY)

1. Remove the integration relay from the engine room relay block.

2. Inspect the EFI MAIN fuse and the IG2 MAIN fuse.

   1. Remove the EFI MAIN fuse and IG2 MAIN fuse from the integration relay.

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

      Standard Resistance:

      Tester Connection	Condition	Specified Condition
      EFI MAIN fuse	Always	Below 1 ?
      IG2 MAIN fuse	Always	Below 1 ?

3. Inspect the EFI relay and the IG2 relay.

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

      Standard Resistance:

      Tester Connection	Condition	Specified Condition
      1C-1 - 1B-4	Battery voltage is not applied to terminals 1B-2 and 1B-3	10 k? or higher
      	Battery voltage is applied to terminals 1B-2 and 1B-3	Below 1 ?
      1C-1 - 1B-8	Battery voltage is not applied to terminals 1B-7 and 1B-6	10 k? or higher
      	Battery voltage is applied to terminals 1B-7 and 1B-6	Below 1 ?

NG	REPLACE INTEGRATION RELAY

OK

3.CHECK HARNESS AND CONNECTOR (+B, +B2 AND MREL CIRCUIT)

1. Check the harness and the connectors between the integration relay and the ECM.

   1. Remove the integration relay from the engine room relay block.

   2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open):

      for LHD

      Tester Connection	Condition	Specified Condition
      A38-44 (MREL) - 1B-2	Always	Below 1 ?
      A38-2 (+B) - 1B-4	Always	Below 1 ?
      A38-1 (+B2) - 1B-4	Always	Below 1 ?

      for RHD

      Tester Connection	Condition	Specified Condition
      A52-44 (MREL) - 1B-2	Always	Below 1 ?
      A52-2 (+B) - 1B-4	Always	Below 1 ?
      A52-1 (+B2) - 1B-4	Always	Below 1 ?

      Standard Resistance (Check for Short):

      for LHD

      Tester Connection	Condition	Specified Condition
      A38-44 (MREL) or 1B-2 - Body ground	Always	10 k? or higher
      A38-2 (+B) or 1B-4 - Body ground	Always	10 k? or higher
      A38-1 (+B2) or 1B-4 - Body ground	Always	10 k? or higher

      for RHD

      Tester Connection	Condition	Specified Condition
      A52-44 (MREL) or 1B-2 - Body ground	Always	10 k? or higher
      A52-2 (+B) or 1B-4 - Body ground	Always	10 k? or higher
      A52-1 (+B2) or 1B-4 - Body ground	Always	10 k? or higher

2. Check the harness and connectors between the integration relay and body ground.

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

      Standard Resistance (Check for Open):

      Tester Connection	Condition	Specified Condition
      1B-3 - Body ground	Always	Below 1 ?

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

1. Disconnect the ECM connector.

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

   Standard Resistance (Check for Open):

   for LHD

   Tester Connection	Condition	Specified Condition
   C45-81 (E1) - Body ground	Always	Below 1 ?

   for RHD

   Tester Connection	Condition	Specified Condition
   C46-81 (E1) - Body ground	Always	Below 1 ?

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.INSPECT ECM (IGSW VOLTAGE)

1. Disconnect the ECM connector.

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

   Standard Voltage:

   for LHD

   Tester Connection	Switch Condition	Specified Condition
   A38-28 (IGSW) - C45-81 (E1)	Ignition switch ON	11 to 14 V

   for RHD

   Tester Connection	Switch Condition	Specified Condition
   A52-28 (IGSW) - C46-81 (E1)	Ignition switch ON	11 to 14 V

NG	Go to step 6

OK
REPLACE ECM

6.INSPECT FUSE (IGN)

1. Remove the IGN fuse from the engine room relay block.

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

   Standard Resistance (Check for Open):

   Tester Connection	Condition	Specified Condition
   IGN fuse	Always	Below 1 ?

NG	CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE

OK

7.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, INTEGRATION RELAY - BODY GROUND)

1. Remove the integration relay from the engine room relay block.

2. Disconnect the ECM connector.

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

   Standard Resistance (Check for Open):

   for LHD

   Tester Connection	Condition	Specified Condition
   1B-8 - A38-28 (IGSW)	Always	Below 1 ?

   for RHD

   Tester Connection	Condition	Specified Condition
   1B-8 - A52-28 (IGSW)	Always	Below 1 ?

   Standard Resistance (Check for Short):

   for LHD

   Tester Connection	Condition	Specified Condition
   1B-8 or A38-28 (IGSW) - Body ground	Always	10 k? or higher

   for RHD

   Tester Connection	Condition	Specified Condition
   1B-8 or A52-28 (IGSW) - Body ground	Always	10 k? or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.CHECK IF VEHICLE IS EQUIPPED WITH ENTRY AND START SYSTEM

Result

Result	Proceed to
w/ Entry and Start System	A
w/o Entry and Start System	B

B	Go to step 11

A

9.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ENGINE ROOM RELAY BLOCK)

1. Remove the integration relay from the engine room relay block.

2. Disconnect the E2 main body ECU connector.

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

   Standard Resistance (Check for Open):

   Tester Connection	Condition	Specified Condition
   E2-11 (IG2D) - 1B-6	Always	Below 1 ?

   Standard Resistance (Check for Short):

   Tester Connection	Condition	Specified Condition
   E2-11 (IG2D) or 1B-6 - Body ground	Always	10 k? or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.CHECK ENTRY AND START SYSTEM (POWER SOURCE MODE DOES NOT CHANGE)

1. Check the entry and start system .

NG	REPAIR ENTRY AND START SYSTEM

OK
REPLACE ECM

11.CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - ENGINE ROOM RELAY BLOCK)

1. Remove the integration relay from the engine room relay block.

2. Disconnect the E93 ignition switch connector.

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

   Standard Resistance (Check for Open):

   Tester Connection	Condition	Specified Condition
   E93-6 (IG2) - 1B-6	Always	Below 1 ?

   Standard Resistance (Check for Short):

   Tester Connection	Condition	Specified Condition
   E93-6 (IG2) or 1B-6 - Body ground	Always	10 k? or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

12.INSPECT IGNITION SWITCH ASSEMBLY

1. Inspect the ignition switch assembly .

NG	REPLACE IGNITION SWITCH ASSEMBLY

OK
REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY)