AUTOMATIC TRANSAXLE SYSTEM ECU Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), voltage from the MREL terminal of the ECM is applied to the EFI-MAIN relay. This causes the contacts of the EFI-MAIN relay to close, which supplies power to terminal +B of the TCM.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

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

   
   

   1. Disconnect the D39 TCM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition D39-8 (E1) - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

2. INSPECT ECU TERMINAL VOLTAGE (+B TERMINAL)

   
   

   1. Disconnect the D39 TCM connector.

   2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition D39-18 (+B) - Body ground Engine switch on (IG) 11 to 14 V

      Result
      Proceed to OK NG

   
   

   OK

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

   NG

3. CHECK HARNESS AND CONNECTOR (TCM - NO. 1 INTEGRATION RELAY)

   
   

   1. Remove the No. 1 integration relay.

      Click here

   2. Disconnect the D39 TCM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition D39-18 (+B) - 1E-10 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition D39-18 (+B) or 1E-10 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   GO TO ECM POWER SOURCE CIRCUIT (ENGINE CONTROL SYSTEM / SFI SYSTEM) Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR