P0A08

P310 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A08-264: DC / DC Converter Status Circuit

DTC P0A08-264 - DC / DC Converter Status Circuit

DESCRIPTION

The DC/DC converter converts the DC 288 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 288 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 DC/DC converter controls the output voltage in order to keep a constant voltage at the terminals of the auxiliary battery.

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

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 disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals. After waiting 5 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be OV before begining work.
HINT: Waiting for at least 5 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT (HV)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:

B -- GO TO DTC CHART Diagnostic Trouble Code Descriptions
A -- Continue to next step.
2. CHECK RELAY BLOCK ASSEMBLY

(a) Check the condition of the fusible links (ALT and MAIN) and fuse (DC/DC-S) in the relay block. Check if the circuits are open.
OK:
They are connected securely. There are no open circuits in the fuse or fusible links.
NG -- REPLACE FUSIBLE LINK OR FUSE, OR REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

(a) Check the connections of the hybrid vehicle control ECU connectors.
OK:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
4. CHECK CONNECTOR CONNECTION CONDITION (MG ECU CONNECTOR)
CAUTION: Be sure to wear insulated gloves.
(a) Turn the power switch off.
(b) Remove the service plug grip Removal.
NOTE: After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.
(c) Remove the inverter cover Removal.
NOTICE:
- Wrap the round interlock terminal for the inverter cover with insulating tape to prevent it from shorting to ground.
- Prevent coolant in the inverter reserve tank from entering the inverter.
- Removing the inverter cover causes the MG ECU board to be exposed. Therefore, temporarily install the inverter cover for each area to be inspected.

(d) Check the connections of the MG ECU connectors.
OK:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
5. CHECK INSULATION RESISTANCE OF HIGH-VOLTAGE SYSTEM
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.

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

HINT: Perform this inspection while the three-phase AC cable for MG2 is connected.

NG -- INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG2 AND MG1)
OK -- Continue to next step.
6. CHECK CONNECTION CONDITION (AMD TERMINAL)
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.
(b) Remove the three-phase AC cable for MGR from the inverter with converter assembly.

(c) Check the connection of the AMD terminal.
OK:
The terminal is connected securely and there are no contact problems.
NG -- CHECK AMD TERMINAL
OK -- Continue to next step.
7. CHECK TERMINAL VOLTAGE (AMD TERMINAL)
CAUTION: Be sure to wear insulated gloves.
(a) Turn the power switch off.
(b) Check that the service plug grip is not installed.

NG -- CHECK TERMINAL VOLTAGE (AMD TERMINAL)
OK -- Continue to next step.
8. CHECK INVERTER WITH CONVERTER ASSEMBLY (MG ECU)
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.
(b) Turn the power switch on (IG).
NOTE: After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.
HINT: Turning the power switch on (IG) with the service grip and inverter cover removed causes interlock switch system DTC P0A0D-350 to be output.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (RESISTANCE VALUE OF NODD INSIDE HYBRID VEHICLE CONTROL ECU)
(a) Turn the power switch off.
(b) Disconnect the A42 connector from the MG ECU.

NG -- INSPECT HYBRID VEHICLE CONTROL ECU
OK -- Continue to next step.
10. INSPECT INVERTER WITH CONVERTER ASSEMBLY (OPERATION OF DC/DC CONVERTER)
HINT: The current at the AMD terminal cannot be measured directly because of space limitations. Measure the current flowing from the auxiliary battery instead.

(a) Connect the AC/DC 400 A probe to the positive auxiliary battery line.
(b) Install the inverter cover Removal.
(c) Install the service plug grip.
(d) 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.

(e) Measure the current flowing from the auxiliary battery with the headlight position switch and blower motor switch in the HI position, and the rear window defogger turned on.
(f) Measure the auxiliary battery voltage according to the previous conditions with the lights, blower motor and rear window defogger turned on.
Result:

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

11. CHECK QUANTITY OF HV COOLANT P0A01-725
C -- CHECK FOR COOLANT LEAKS AND ADD COOLANT
B -- ADD HV COOLANT
A -- Continue to next step.

12. CHECK COOLANT HOSE P0A01-725
NG -- CORRECT THE PROBLEM
OK -- Continue to next step.

13. CHECK CONNECTOR CONNECTION CONDITION (WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY CONNECTOR) P0A01-725
NG -- CONNECT SECURELY
OK -- Continue to next step.

14. PERFORM ACTIVE TEST USING TECHSTREAM (WATER PUMP) P0A01-725
NG -- CHECK FUSE (INV-W/P)
OK -- Continue to next step.

15. PERFORM ACTIVE TEST USING TECHSTREAM (COOLING FAN) P0A01-725
NG -- CHECK COOLING FAN SYSTEM
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

16. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG2 AND MG1)
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.

(b) Disconnect the three-phase AC cables for the hybrid vehicle transaxle assembly (MG2 and MG1) from the inverter with converter assembly.

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

NG -- REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
OK -- Continue to next step.
17. INSPECT REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY
CAUTION: Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.
(b) Disconnect the three-phase AC cable for MGR from the inverter with converter assembly.

NG -- INSPECT REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
18. CHECK AMD TERMINAL
CAUTION: Be sure to wear insulated gloves.

(a) Check for arc marks on the AMD terminals (inverter with converter assembly side and wire harness side).
OK:
There are no arc marks.
HINT: The wire harness between the AMD terminal on the inverter with converter assembly side and the AMD terminal on the vehicle side is supplied with the inverter with converter assembly as a unit. If the wire harness is faulty, replace the inverter with converter assembly.

NG -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
OK -- CONNECT SECURELY
19. CHECK TERMINAL VOLTAGE (AMD TERMINAL)

(a) Turn the power switch off.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
20. INSPECT HYBRID VEHICLE CONTROL ECU

(a) Disconnect all hybrid vehicle control ECU connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPLACE HYBRID VEHICLE CONTROL ECU
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
21. INSPECT REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.

(b) Disconnect the No. 3 frame wire (three-phase AC cable for MGR) from the rear traction motor with transaxle assembly.

NOTE: Wrap terminals U, V, and W of the No. 3 frame wire (three-phase AC cable for MGR) on the inverter with converter assembly side with insulating tape to prevent the terminals from shorting to ground.

NG -- REPLACE NO. 3 FRAME WIRE
OK -- REPLACE REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY

22. CHECK FUSE (INV-W/P) P0A01-725
NG -- REPLACE FUSE (INV-W/P)
OK -- Continue to next step.

23. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - WATER PUMP) P0A01-725
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- INSPECT WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY CIRCUIT