ECU Power Source Circuit

HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: ECU Power Source Circuit
- ECU Power Source Circuit

DESCRIPTION

If the power switch is on (IG), the power management control ECU 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 P0A08.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK POWER MANAGEMENT CONTROL ECU (+B1, +B2 VOLTAGE)

(a) Turn the power switch on (IG).

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





Standard Voltage:





Text in Illustration





(c) Turn the power switch off.

NG -- CHECK POWER MANAGEMENT CONTROL ECU (MREL VOLTAGE)
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BODY GROUND)

(a) Disconnect connector I3 and I4 from the power management control ECU.

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





Standard Resistance:





Text in Illustration





(c) Connect the power management control ECU connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- GO TO PROBLEM SYMPTOMS TABLE Problem Symptoms Table

3. CHECK POWER MANAGEMENT CONTROL ECU (MREL VOLTAGE)

(a) Turn the power switch on (IG).

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





Standard Voltage:





Text in Illustration





NG -- REPLACE POWER MANAGEMENT CONTROL ECU Components
OK -- Continue to next step.

4. CHECK FUSE (PM IGCT)

(a) Remove the PM IGCT fuse from the No. 2 engine room relay block.





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

Standard Resistance:





Text in Illustration





(c) Install the PM IGCT fuse.

NG -- CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 ENGINE ROOM RELAY BLOCK)
OK -- Continue to next step.

5. CHECK FUSE (IGCT-MAIN) P0A08

NG -- CHECK HARNESS AND CONNECTOR (NO. 2 ENGINE ROOM RELAY BLOCK)
OK -- Continue to next step.

6. INSPECT RELAY (IGCT)

(a) Remove the IGCT relay from the No. 2 engine room relay block.

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





Standard Resistance:





Text in Illustration





(c) Install the IGCT relay.

NG -- REPLACE RELAY (IGCT)
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 ENGINE ROOM RELAY BLOCK)

(a) Remove the PM IGCT fuse from the No. 2 engine room relay block.





Text in Illustration





(b) Disconnect connector A38 and A39 from the power management control ECU.

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





Text in Illustration





Standard Resistance:





(d) Install the PM IGCT fuse.

(e) Connect the power management control ECU connectors.

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

8. CHECK HARNESS AND CONNECTOR (NO. 2 ENGINE ROOM RELAY BLOCK)

(a) Remove the IGCT-MAIN fuse and PM IGCT fuse from the No. 2 engine room relay block.





Text in Illustration





(b) Remove the IGCT relay from the No. 2 engine room relay block.

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





Standard Resistance:





Text in Illustration





(d) Install the IGCT-MAIN fuse and PM IGCT fuse.

(e) Install the IGCT relay.

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

9. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 ENGINE ROOM RELAY BLOCK)

(a) Remove the IGCT relay from the No. 2 engine room relay block.

(b) Disconnect connector A39 from the power management control ECU.

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





Text in Illustration





Standard Resistance:





(d) Install the IGCT relay.

(e) Connect the power management control ECU connectors.

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

10. CHECK HARNESS AND CONNECTOR (NO. 2 ENGINE ROOM RELAY BLOCK - BODY GROUND)

(a) Remove the IGCT relay from the No. 2 engine room relay block.

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





Standard Resistance:





Text in Illustration





(c) Install the IGCT relay.

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

11. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - NO. 2 ENGINE ROOM RELAY BLOCK)

(a) Remove the IGCT-MAIN fuse from the No. 2 engine room relay block.

(b) Disconnect AMD terminal from the engine room relay block and junction block assembly.

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





Text in Illustration





Standard Resistance:





(d) Install the IGCT-MAIN fuse.

(e) Connect AMD terminal.

NG -- CHECK FUSIBLE LINK BLOCK ASSEMBLY (R/B NO. 2)

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

12. CHECK FUSIBLE LINK BLOCK ASSEMBLY (R/B NO. 2)

(a) Check the fusible link block assembly (R/B NO. 2) in the engine room relay block and junction block assembly for improper installation.

OK:

The fusible link is installed securely.

(b) Remove the fusible link block assembly from the engine room relay block and junction block assembly.

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





Standard Resistance:





Text in Illustration





(d) Install the fusible link block assembly.

NG -- REPLACE FUSIBLE LINK BLOCK ASSEMBLY (R/B NO. 2)

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

13. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 ENGINE ROOM RELAY BLOCK)

(a) Disconnect connector E11 from the shift lever position sensor.

(b) Remove the PM IGCT fuse from the No. 2 engine room relay block.





Text in Illustration





(c) Disconnect connectors A38 and A39 from the power management control ECU.

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





Text in Illustration





Standard Resistance:





(e) Install the PM IGCT fuse.

(f) Connect the shift lever position sensor connector.

(g) Connect the power management control ECU connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE FUSE (PM IGCT)

14. REPAIR OR REPLACE HARNESS OR CONNECTOR

NEXT -- REPLACE FUSE (PM IGCT)

15. CHECK HARNESS AND CONNECTOR (NO. 2 ENGINE ROOM RELAY BLOCK)

(a) Remove the IGCT-MAIN fuse and PM IGCT fuse from the No. 2 engine room relay block.





Text in Illustration





(b) Remove the IGCT relay from the No. 2 engine room relay block.

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





Standard Resistance:





Text in Illustration





(d) Install the IGCT-MAIN fuse and PM IGCT fuse.

(e) Install the IGCT relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE FUSE (IGCT-MAIN)

16. REPAIR OR REPLACE HARNESS OR CONNECTOR

NEXT -- REPLACE FUSE (IGCT-MAIN)