P0A08

HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: P0A08-264: DC / DC Converter Status Circuit
P0A08-264 - DC / DC Converter Status Circuit

DESCRIPTION

The hybrid vehicle converter (DC/DC converter) converts the DC 201.6 V of the HV battery into DC 12 V in order to supply power to areas such as the vehicle's lighting, audio, and ECU systems. In addition, it charges the auxiliary battery. A transistor bridge circuit initially converts DC 201.6 V into alternating current, and a transformer lowers its voltage. Then, it is rectified and smoothed (into DC) and converted into DC 12 V. The hybrid vehicle converter controls the output voltage in order to keep a constant voltage at the terminals of the auxiliary battery.

The power management control ECU (HV CPU) uses the NODD signal line to transmit a stop command to the hybrid vehicle converter and receive signals indicating the normal or abnormal condition of the 12 V charging system. If the vehicle is being driven with an inoperative hybrid vehicle converter, the voltage of the auxiliary battery will drop, which will prevent the continued operation of the vehicle. Therefore, the power management control ECU (HV CPU) monitors the operation of the hybrid vehicle converter and alerts the driver if it detects a malfunction.

WIRING DIAGRAM

INSPECTION PROCEDURE

CAUTION:
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work Hybrid Control System: Precaution.
HINT
Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Service Precautions.

PROCEDURE

1. CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Result:

(e) Turn the power switch off.

B -- GO TO DTC CHART (HYBRID CONTROL SYSTEM) Hybrid Control System
A -- Continue to next step.

2. CHECK FUSE (IGCT NO. 2)

(a) Disconnect the cable from the negative auxiliary battery terminal.

(b) Remove the IGCT No. 2 fuse from the engine room junction block assembly.

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

Standard Resistance:

Text in Illustration

(d) Install the IGCT No. 2 fuse.

NG -- CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - IGCT NO. 2 FUSE)
OK -- Continue to next step.

3. CHECK FUSE (DC/DC-S)

(a) Remove the DC/DC-S fuse from the engine room junction block assembly.

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

Standard Resistance:

Text in Illustration

(c) Install the DC/DC-S fuse.

NG -- CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - DC/DC-S FUSE)
OK -- Continue to next step.

4. CHECK FUSE (IGCT)

(a) Remove the IGCT fuse from the engine room junction block assembly.

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

Standard Resistance:

Text in Illustration

(c) Install the IGCT fuse.

NG -- CHECK ENGINE ROOM JUNCTION BLOCK (IGCT RELAY, IGCT FUSE, IGCT NO. 2 FUSE)
OK -- Continue to next step.

5. CHECK FUSIBLE LINK (DC/DC)

(a) Disconnect connector 1E from the engine room junction block assembly.

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

Standard Resistance:

(c) Check the fusible links (DC/DC) in the engine room junction block assembly for improper installation.

OK:

The fusible link is installed securely.

(d) Connect the engine room junction block assembly connector.

NG -- REPLACE FUSIBLE LINK (DC/DC)
OK -- Continue to next step.

6. CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) P0340

NG -- CONNECT SECURELY
OK -- Continue to next step.

7. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR) P0343

NG -- CONNECT SECURELY
OK -- Continue to next step.

8. CHECK CABLE AND WIRE HARNESS

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Remove the inverter cover from the inverter with converter assembly.

NOTICE:
Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard Resistance:

Text in Illustration

HINT
Perform this inspection while the three-phase AC cable for MG1 and for MG2 are connected.

(d) Install the inverter cover to the inverter with converter assembly.

NG -- CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG1)
OK -- Continue to next step.

9. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY (AMD TERMINAL CONNECTION CONDITION)

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Check that the bolt for the AMD terminal is tightened to the specified torque, the AMD terminal is connected securely, and there is no contact problem.

Torque:

T=8.3 N*m {85 kgf*cm, 73 in.*lbf }

Result:

C -- REPLACE MALFUNCTIONING PARTS

B -- CONNECT SECURELY
A -- Continue to next step.

10. CHECK TERMINAL VOLTAGE (AMD TERMINAL VOLTAGE)

CAUTION:
Be sure to wear insulated gloves.

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

Standard Voltage:

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

11. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK - INVERTER WITH CONVERTER)

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Disconnect connector A62 from the inverter with converter assembly.

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

Standard Voltage:

Text in Illustration

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

HINT
Turning the power switch on (IG) with the service grip removed causes interlock switch system DTC P0A0D-350 to be output.

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

Standard Voltage:

NOTICE:
Turning the power switch on (IG) with the inverter with converter assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

(f) Turn the power switch off.

(g) Connect the inverter with converter assembly connector.

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

12. CHECK POWER MANAGEMENT CONTROL ECU

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Disconnect connector A62 from the inverter with converter assembly.

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

Standard Resistance:

Text in Illustration

(d) Connect the inverter with converter assembly connector.

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

13. CHECK DC/DC CONVERTER FUNCTION

HINT
The current at the AMD terminal cannot be measured directly because of space limitations. Measure the current flowing at the auxiliary battery instead.

(a) Connect the AC/DC 400 A probe to the positive auxiliary battery line.

(b) Install the service plug grip.

(c) Turn the power switch on (READY) and leave the vehicle as it is until the electric current flowing into the auxiliary battery becomes 10 A or less.

(d) Measure the current flowing from the auxiliary battery with the power switch on (READY), the headlight position switch and blower motor switch in the HI position, and the rear window defogger turned on.

Standard Current:

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

Standard Voltage:

(f) Turn the power switch off.

NG -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components
OK -- Continue to next step.

14. CHECK QUANTITY OF HV COOLANT P0A01

C -- INSPECT FOR COOLANT LEAK AND ADD COOLANT

B -- ADD HV COOLANT
A -- Continue to next step.

15. CHECK COOLANT HOSE P0A01

NG -- CORRECT THE PROBLEM
OK -- Continue to next step.

16. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE ELECTRIC COOLING FAN) P0A01

NG -- CHECK COOLING FAN SYSTEM Cooling Fan Circuit
OK -- Continue to next step.

17. CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)

(a) Connect the Techstream to the DLC3.

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

(c) Read the freeze frame data Ambient Temperature using the Techstream.

(d) Check if the freeze frame data Ambient Temperature is below freezing.

Result:

HINT
- HV coolant (SLLC) with a 30% concentration freezes at 5°F (-15 °C) and HV coolant (SLLC) with a 50% concentration freezes at -31°F (-35°C).
- If the HV coolant freezes in the HV radiator or HV water pump, the coolant temperature in the inverter with converter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be set.
- A DTC is set when the water pump impeller cannot rotate due to freezing of the HV coolant.
- If a DTC is set due to freezing of HV coolant, the problem cannot be reproduced. Judge whether freezing of HV coolant occurred according to the freeze point of the HV coolant, HV coolant change history and ambient temperature when the DTC was set.

(e) Turn the power switch off.

B -- REPLACE HV COOLANT

A -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components

18. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG1)

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Remove the inverter cover from the inverter with converter assembly.

Text in Illustration

(d) Using a megohmmeter set to 500 V, measure the insulation resistance according to the value(s) in the table below.

NOTICE:
Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard Resistance:

Text in Illustration

(e) Connect the three-phase AC cables for MG1 to the inverter with converter assembly.

(f) Install the inverter cover to the inverter with converter assembly.

NG -- CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)
OK -- Continue to next step.

19. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG2)

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Remove the inverter cover from the inverter with converter assembly.

Text in Illustration

(d) Using a megohmmeter set to 500 V, measure the insulation resistance according to the value(s) in the table below.

NOTICE:
Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard Resistance:

Text in Illustration

(e) Connect the three-phase AC cables for MG2 to the inverter with converter assembly.

(f) Install the inverter cover to the inverter with converter assembly.

NG -- CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)

OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components

20. INSPECT POWER MANAGEMENT CONTROL ECU

(a) Disconnect all the connectors 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 -- REPLACE POWER MANAGEMENT CONTROL ECU Components

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

21. REPLACE HV COOLANT P0A01

NEXT -- Continue to next step.

22. CHECK INVERTER WATER PUMP ASSEMBLY P0A01

NG -- REPLACE INVERTER WATER PUMP ASSEMBLY Components

OK -- COMPLETED

23. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION) P0A78

C -- CONNECT SECURELY

B -- REPLACE MALFUNCTIONING PARTS
A -- Continue to next step.

24. CHECK GENERATOR CABLE P0A78

NG -- REPLACE GENERATOR CABLE Components

OK -- REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Components

25. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR CABLE CONNECTION CONDITION) P0A78

C -- CONNECT SECURELY

B -- REPLACE MALFUNCTIONING PARTS
A -- Continue to next step.

26. CHECK MOTOR CABLE P0A78

NG -- REPLACE MOTOR CABLE Components

OK -- REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Components

27. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - IGCT NO. 2 FUSE)

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.

(b) Disconnect connector A62 from the inverter with converter assembly.

(c) Remove the IGCT No. 2 fuse from the engine room junction block assembly.

Text in Illustration

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

Text in Illustration

Standard Resistance:

(e) Install the IGCT No. 2 fuse.

(f) Connect the inverter with converter assembly connector.

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

28. REPLACE INVERTER WITH CONVERTER ASSEMBLY

(a) Replace the inverter with converter assembly Components.

NEXT -- REPLACE FUSE (IGCT NO. 2)

29. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - DC/DC-S FUSE)

(a) Disconnect connector A62 from the inverter with converter assembly.

(b) Remove the DC/DC-S fuse from the engine room junction block assembly.

Text in Illustration

Standard Resistance:

(d) Install the DC/DC-S fuse.

(e) Connect the inverter with converter assembly connector.

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

30. REPLACE INVERTER WITH CONVERTER ASSEMBLY

(a) Replace the inverter with converter assembly Components.

NEXT -- REPLACE FUSE (DC/DC-S)

31. CHECK ENGINE ROOM JUNCTION BLOCK (IGCT RELAY, IGCT FUSE, IGCT NO. 2 FUSE)

(a) Remove the IGCT relay, IGCT fuse and IGCT No. 2 fuse from the engine room junction block assembly.

Text in Illustration

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

Standard Resistance:

Text in Illustration

(c) Install the IGCT relay, IGCT fuse and IGCT No. 2 fuse.

NG -- REPAIR OR REPLACE ENGINE ROOM JUNCTION BLOCK

OK -- REPLACE FUSE (IGCT)

32. REPAIR OR REPLACE HARNESS OR CONNECTOR

NEXT -- REPLACE FUSE (IGCT NO. 2)

33. REPAIR OR REPLACE HARNESS OR CONNECTOR

NEXT -- REPLACE FUSE (DC/DC-S)

34. REPAIR OR REPLACE ENGINE ROOM JUNCTION BLOCK

NEXT -- REPLACE FUSE (IGCT)