Component Tests and General Diagnostics

1GR-FE ENGINE CONTROL SYSTEM: 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 the IGSW terminal 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 No. 1 integration relay (EFI relay) and supplying power to either terminal +B or +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 (BATTERY - NO. 1 INTEGRATION RELAY)





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

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

Standard Voltage:





Text in Illustration





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

2. INSPECT NO. 1 INTEGRATION RELAY (EFI)

(a) Inspect the No. 1 integration relay (EFI) Component Tests and General Diagnostics.

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 junction block.

(2) Disconnect the ECM connector.

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

Standard Resistance:





(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:





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:





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

5. INSPECT ECM (IGSW VOLTAGE)





(a) Disconnect the ECM connectors.

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

Standard Voltage:





Text in Illustration





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) Component Tests and General Diagnostics.

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

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

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

(b) Disconnect the ECM 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.

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

(a) Check the harness and connectors between the No. 1 integration relay and ignition switch assembly.

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

(2) Disconnect the ignition switch assembly connector.

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

Standard Resistance:





(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:





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

9. INSPECT IGNITION SWITCH ASSEMBLY

(a) Inspect the ignition switch assembly Testing and Inspection.

NG -- REPLACE IGNITION SWITCH ASSEMBLY Removal

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