ECM Power Source Circuit

2ZR-FXE ENGINE CONTROL: SFI SYSTEM: ECM Power Source Circuit
- ECM Power Source Circuit

DESCRIPTION

When the power switch is turned on (IG), auxiliary battery voltage is applied to 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 and +B2 of the ECM.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

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

(a) Disconnect the ECM connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. INSPECT ECM (IGSW VOLTAGE)

(a) Disconnect the ECM connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





NG -- INSPECT INTEGRATION RELAY (IG2 RELAY)
OK -- Continue to next step.

3. INSPECT INTEGRATION RELAY (EFI MAIN RELAY)

(a) Inspect the integration relay Inspection.

NG -- REPLACE INTEGRATION RELAY Removal
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - ECM)

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

(c) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - AUXILIARY BATTERY)

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

(c) Disconnect the negative (-) auxiliary battery terminal.

(d) Disconnect the positive (+) auxiliary battery terminal.

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

Standard Resistance (Check for Open):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

7. INSPECT INTEGRATION RELAY (IG2 RELAY)

(a) Inspect the integration relay Inspection.

NG -- REPLACE INTEGRATION RELAY Removal
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - ECM)

(a) Disconnect the ECM connector.

(b) Remove the integration relay from the engine room relay block.

(c) Disconnect the integration relay connector.

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

Standard Resistance (Check for Open):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

9. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - AUXILIARY BATTERY)

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

(c) Disconnect the negative auxiliary battery terminal.

(d) Disconnect the positive auxiliary battery terminal.

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

Standard Resistance (Check for Open):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

10. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

11. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INTEGRATION RELAY (IG2 RELAY))

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

(c) Disconnect the power management control ECU connector.

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

Standard Resistance (Check for Open):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- CHECK SMART KEY SYSTEM How To Proceed With Troubleshooting