Component Tests and General Diagnostics

1GR-FE ENGINE CONTROL: SFI SYSTEM: ECM Power Source Circuit
- 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 output signal from the MREL terminal of the ECM causes a current to flow to the coil of the No. 1 integration relay (EFI MAIN), closing the contacts and supplying power to both 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. INSPECT NO. 1 INTEGRATION RELAY (NO. 1 INTEGRATION RELAY - BODY GROUND)

(a) Remove the No. 1 integration relay from the engine room relay block.





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

Standard Voltage:





Text in Illustration





(c) Reinstall the No. 1 integration relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY - BATTERY)
OK -- Continue to next step.

2. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN)

(a) Inspect the No. 1 integration relay (EFI MAIN) Testing and Inspection.

NG -- REPLACE NO. 1 INTEGRATION RELAY
OK -- Continue to next step.

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

(a) Check the harness and connectors between the No. 1 integration relay and ECM.

(1) Remove the No. 1 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):





Standard Resistance (Check for Short):





(b) Check the harness and connectors between the No. 1 integration relay and body ground.

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

Standard Resistance (Check for Open):





(c) Reinstall the No. 1 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 ECM connector.

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

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 ECM connectors.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





Text in Illustration





(d) Reconnect the ECM connectors.

NG -- INSPECT NO. 1 INTEGRATION RELAY (IG2)

OK -- REPLACE ECM Removal

6. INSPECT NO. 1 INTEGRATION RELAY (IG2)

(a) Inspect the No. 1 integration relay (IG2) Testing and Inspection.

NG -- REPLACE NO. 1 INTEGRATION RELAY (IG2)
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2) - ECM)

(a) Remove the No. 1 integration relay (IG2) from the engine room relay block.

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reinstall the No. 1 integration relay (IG2).

(e) Reconnect the ECM connector.

Result





C -- CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2) - IGNITION SWITCH ASSEMBLY)

B -- CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2) - POWER MANAGEMENT CONTROL ECU)

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR

8. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2) - POWER MANAGEMENT CONTROL ECU)

(a) Remove the No. 1 integration relay (IG2) from the engine room relay block.

(b) Disconnect the power management control ECU connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reinstall the No. 1 integration relay (IG2).

(e) Reconnect the power management control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- CHECK SMART KEY SYSTEM

9. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2) - IGNITION SWITCH ASSEMBLY)

(a) Remove the No. 1 integration relay (IG2) from the engine room relay block.

(b) Disconnect the ignition switch connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reinstall the No. 1 integration relay (IG2).

(e) Reconnect the ignition switch connector.

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

10. INSPECT IGNITION SWITCH

(a) Inspect the ignition switch Testing and Inspection.

NG -- REPLACE IGNITION SWITCH Removal

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