SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes current to flow to the coil of the EFI-MAIN NO. 1 relay, closing the contacts and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (ECM VOLTAGE)

   
   
   1. 

      *a	Rear view of wire harness connector (to ECM)

      Disconnect the ECM connector.

   2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition G46-8 (IGSW) - Body ground Ignition switch ON 11 to 14 V

      Result
      Result Proceed to OK A NG B

   
   

   B

   CHECK HARNESS AND CONNECTOR (BATTERY - IGNITION SWITCH ASSEMBLY) Click here

   A

2. CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   
   
   1. 

      *a	Front view of wire harness connector (to Instrument Panel Junction Block Assembly)

      Disconnect the instrument panel junction block assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition 2B-1 - Body ground Always 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. INSPECT EFI-MAIN NO. 1 RELAY

   
   

   1. Inspect the EFI-MAIN NO. 1 relay.

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   OK

4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)

   
   

   1. Disconnect the instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 2J-5 - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

5. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - ECM)

   
   

   1. Disconnect the instrument panel junction block assembly connector.

   2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 2G-5 - G46-1 (+B) Always Below 1 Ω 2G-5 - G46-2 (+B2) Always Below 1 Ω 2P-9 - G45-6 (MREL) Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. 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
      Tester Connection Condition Specified Condition C52-3 (E1) - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

7. CHECK HARNESS AND CONNECTOR (BATTERY - IGNITION SWITCH ASSEMBLY)

   
   
   1. 

      *a	Front view of wire harness connector (to Ignition Switch)

      Disconnect the ignition switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition G1-4 (AM2) - Body ground Always 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

8. INSPECT IGNITION SWITCH ASSEMBLY

   
   

   1. Inspect the ignition switch assembly.

      Click here

      Result
      Proceed to OK NG

   
   

   OK

   REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH ASSEMBLY - ECM)

   NG

   REPLACE IGNITION SWITCH ASSEMBLY Click here