HYBRID CONTROL SYSTEM ECU Power Source Circuit

DESCRIPTION

If the power switch is on (IG), the hybrid vehicle control ECU assembly applies current to the MREL terminal to turn the IGCT relay on. This supplies power to the +B1 and +B2 terminals.

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0A08-264.

Click here

PROCEDURE

1. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (+B1, +B2 VOLTAGE)

   
   

   1. Turn the power switch on (IG).

   2. 

      *a	Component with harness connected (Hybrid Vehicle Control ECU Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition A81-4 (+B1) - Body ground Power switch on (IG) 11 to 14 V A80-1 (+B2) - Body ground Power switch on (IG) 11 to 14 V

   3. Turn the power switch off.

      Result
      Proceed to OK NG

   
   

   NG

   CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (MREL VOLTAGE) Click here

   OK

2. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - BODY GROUND)

   
   

   1. Disconnect the O141 and O142 hybrid vehicle control ECU assembly connectors.

   2. 

      *a	Rear view of wire harness connector (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition O141-5 (E01) - Body ground Always Below 1 Ω O141-6 (E1) - Body ground Always Below 1 Ω O142-4 (E12) - Body ground Always Below 1 Ω O142-5 (E02) - Body ground Always Below 1 Ω

   3. Reconnect the O141 and O142 hybrid vehicle control ECU assembly connectors.

      Result
      Proceed to OK NG

   
   

   OK

   GO TO PROBLEM SYMPTOMS TABLE Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

3. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (MREL VOLTAGE)

   
   

   1. Turn the power switch on (IG).

   2. 

      *a	Component with harness connected (Hybrid Vehicle Control ECU Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition A81-6 (MREL) - Body ground Power switch on (IG) 11 to 14 V

   3. Turn the power switch off.

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

   OK

4. CHECK FUSE (PM-IGCT)

   
   
   1. 

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2	PM-IGCT Fuse

      Remove the PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition PM-IGCT fuse terminals Always Below 1 Ω

   3. 

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2	PM-IGCT Fuse

      Install the PM-IGCT fuse.

      Result
      Proceed to OK NG

   
   

   NG

   CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - HYBRID VEHICLE CONTROL ECU ASSEMBLY) Click here

   OK

5. CHECK FUSE (IGCT NO. 1)

   
   
   1. 

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2	IGCT NO. 1 Fuse

      Remove the IGCT NO. 1 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition IGCT NO. 1 fuse terminals Always Below 1 Ω

   3. Install the IGCT NO. 1 fuse.

      Result
      Proceed to OK NG

   
   

   NG

   CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) Click here

   OK

6. INSPECT RELAY (IGCT)

   
   

   1. Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

   2. 

      *1	IGCT Relay

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

      Standard Resistance
      Tester Connection Condition Specified Condition 3 - 5 Auxiliary battery voltage is not applied between terminals 1 and 2 10 kΩ or higher Auxiliary battery voltage is applied between terminals 1 and 2 Below 1 Ω

   3. Install the IGCT relay.

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE RELAY (IGCT)

   OK

7. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - HYBRID VEHICLE CONTROL ECU ASSEMBLY)

   
   
   1. 

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2	PM-IGCT Fuse

      Remove the PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

   2. Disconnect the A80 and A81 hybrid vehicle control ECU assembly connectors.

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

      

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly	*2	PM-IGCT Fuse
      *a	Rear view of wire harness connector (to Hybrid Vehicle Control ECU Assembly)	-	-

      Standard Resistance
      Tester Connection Condition Specified Condition 2 (PM-IGCT fuse) - A81-4 (+B1) Always Below 1 Ω 2 (PM-IGCT fuse) - A80-1 (+B2) Always Below 1 Ω

   4. Reconnect the A80 and A81 hybrid vehicle control ECU assembly connectors.

   5. Install the PM-IGCT fuse.

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

8. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)

   
   
   1. 

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2	IGCT NO. 1 Fuse
      *3	PM-IGCT Fuse
      *4	IGCT Relay

      Remove the IGCT NO. 1 fuse, PM-IGCT fuse and IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

   2. 

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2	IGCT NO. 1 Fuse
      *3	PM-IGCT Fuse
      *4	IGCT Relay

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

      Standard Resistance
      Tester Connection Condition Specified Condition 3 (IGCT relay) - 2 (IGCT NO. 1 fuse) Always Below 1 Ω 5 (IGCT relay) - 1 (PM-IGCT fuse) Always Below 1 Ω

   3. Install the IGCT NO. 1 fuse, PM-IGCT fuse and IGCT relay.

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

9. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)

   
   

   1. Disconnect the A81 hybrid vehicle control ECU assembly connector.

   2. Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      

      *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly	*2	IGCT Relay
      *a	Rear view of wire harness connector (to Hybrid Vehicle Control ECU Assembly)	-	-

      Standard Resistance
      Tester Connection Condition Specified Condition A81-6 (MREL) - 1 (IGCT relay) Always Below 1 Ω A81-6 (MREL) or 1 (IGCT relay) - Body ground and other terminals Always 10 kΩ or higher

   4. Install the IGCT relay.

   5. Reconnect the A81 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

10. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - BODY GROUND)

    
    

    1. Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	IGCT Relay

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

       Standard Resistance
       Tester Connection Condition Specified Condition 2 (IGCT relay) - Body ground Always Below 1 Ω

    3. Install the IGCT relay.

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

11. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)

    
    

    1. Disconnect the inverter bus-bar plate sub-assembly from the AMD terminal (No. 1 engine room relay block and No. 1 junction block assembly side).

    2. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	AMD Terminal
       *3	IGCT NO. 1 Fuse

       Remove the IGCT NO. 1 fuse and PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

    3. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	IGCT NO. 1 Fuse
       *3	AMD Terminal

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

       Standard Resistance
       Tester Connection Condition Specified Condition 1J-1 (AMD terminal) - 1 (IGCT NO. 1 fuse) Always Below 1 Ω

    4. Install the IGCT NO. 1 fuse.

    5. Reconnect the inverter bus-bar plate sub-assembly from the AMD terminal (No. 1 engine room relay block and No. 1 junction block assembly side).

       Result
       Proceed to OK NG

    
    

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

12. CHECK FUSE (DC/DC)

    Result
    Proceed to OK NG

    
    
    1. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	DC/DC Fuse

       Check the DC/DC fuse in the No. 1 engine room relay block and No. 1 junction block assembly for improper installation.

       OK
       The DC/DC fuse is installed securely.

    2. Remove the DC/DC fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

       Standard Resistance
       Tester Connection Condition Specified Condition DC/DC fuse terminals Always Below 1 Ω

    4. Install the DC/DC fuse.

       Result
       Proceed to OK NG

    
    

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG

    REPLACE FUSE (DC/DC)

13. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)

    
    
    1. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	IGCT Relay

       Remove the IGCT NO. 1 fuse, PM-IGCT fuse and IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	IGCT NO. 1 Fuse
       *3	PM-IGCT Fuse
       *4	IGCT Relay

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

       Standard Resistance
       Tester Connection Condition Specified Condition 3 (IGCT relay) or 2 (IGCT NO. 1 fuse) - Body ground and other terminals Always 10 kΩ or higher 5 (IGCT relay) or 1 (PM-IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher

    3. Install the IGCT NO. 1 fuse, PM-IGCT fuse and IGCT relay.

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE FUSE (IGCT NO. 1)

    NG

14. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to NEXT

    
    

    NEXT

    REPLACE FUSE (IGCT NO. 1)

15. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - HYBRID VEHICLE CONTROL ECU ASSEMBLY)

    
    
    1. 

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
       *2	PM-IGCT Fuse

       Remove the PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Disconnect the A80 and A81 hybrid vehicle control ECU assembly connectors.

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

       

       *1	No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly	*2	PM-IGCT Fuse
       *a	Rear view of wire harness connector (to Hybrid Vehicle Control ECU Assembly)	-	-

       Standard Resistance
       Tester Connection Condition Specified Condition 2 (PM-IGCT fuse) or A81-4 (+B1) - Body ground and other terminals Always 10 kΩ or higher 2 (PM-IGCT fuse) or A80-1 (+B2) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the A80 and A81 hybrid vehicle control ECU assembly connectors.

    5. Install the PM-IGCT fuse.

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE FUSE (PM-IGCT)

    NG

16. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to NEXT

    
    

    NEXT

    REPLACE FUSE (PM-IGCT)