ECM Power Source Circuit

2GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: ECM Power Source Circuit

ECM Power Source Circuit

DESCRIPTION

When the power switch is turned on (IG), the 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 MAIN relay) and supplying power to either terminal +B or +B1 of the ECM.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BODY GROUND)





(a) Remove the integration relay from the engine room No. 1 junction block.
(b) Measure the voltage between the terminal of the wire harness side connector and body ground.
Standard voltage:





(c) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - BATTERY)
OK -- Continue to next step.
2. INSPECT INTEGRATION RELAY (EFI MAIN RELAY)





(a) Remove the integration relay (Unit A) from the engine room No. 1 junction block.
(b) Inspect the EFI fuse.
(1) Remove the EFI fuse from the integration relay.
(2) Measure the resistance of the EFI fuse.
Standard resistance:
Below 1 Ohms
(3) Reinstall the EFI fuse.
(c) Inspect the EFI MAIN relay.
(1) Measure the resistance of the EFI MAIN relay.
Standard resistance:





(d) Reinstall the integration relay.
NG -- REPLACE INTEGRATION RELAY
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (+B, +B1 AND MREL CIRCUIT)





(a) Check the harness and the connectors between the integration relay and the ECM.
(1) Remove the integration relay (Unit A) from the engine room No. 1 junction block.
(2) Disconnect the A53 ECM connector.
(3) Measure the resistance between the terminals of the wire harness side connectors.
Standard resistance (Check for open):






Standard resistance (Check for short):





(b) Check the harness and the connectors between the integration relay and body ground.
(1) Measure the resistance between the terminals of the wire harness side connector and body ground.
Standard resistance (Check for open):





(c) Reinstall the integration relay.
(d) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)





(a) Disconnect the E83 ECM connector.
(b) Measure the resistance.
Standard resistance (Check for open):





(c) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT ECM (IGSW VOLTAGE)





(a) Disconnect the E83 and A53 ECM connectors.
(b) Turn the power switch on (IG).
(c) Measure the voltage between the terminals of the ECM connectors.
Standard voltage:





(d) Reconnect the ECM connectors.
OK -- REPLACE ECM
NG -- Continue to next step.
6. INSPECT FUSE (IGN AND IG2 MAIN FUSE)





(a) Remove the IGN fuse from the main body ECU (cowl side junction block RH).





(b) Remove the IG2 MAIN fuse from the engine room No. 1 relay block.
(c) Measure the resistance of the IGN and IG2 MAIN fuse.
Standard resistance:
Below 1 Ohms
NG -- CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE
OK -- Continue to next step.
7. INSPECT IG2 RELAY





(a) Remove the IG2 relay from the engine room No. 1 relay block.
(b) Measure the resistance of the IG2 relay.
Standard resistance:





(c) Reinstall the relay.
NG -- REPLACE IG2 RELAY
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (ECM - IG2 RELAY)





(a) Remove the IG2 relay from the engine room No. 1 relay block.
(b) Disconnect the A53 ECM connector.
(c) Measure the resistance between the terminal of the wire harness side connectors.
Standard resistance (Check for open):






Standard resistance (Check for short):






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - POWER SOURCE CONTROL ECU)





(a) Remove the IG2 relay from the engine room No. 1 relay block.
(b) Disconnect the K73 power source control ECU connector.
(c) Measure the resistance between the terminal of the wire harness side connectors.
Standard resistance (Check for open):






Standard resistance (Check for short):






OK -- CHECK SMART ACCESS SYSTEM WITH PUSH-BUTTON START
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR