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 HV 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 HV control ECU monitors the operation of the DC/DC converter and alerts the driver if it detects a malfunction.

INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from 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.
HINT: At least 5 minutes is required to discharge the high-voltage capacitor inside the w/ converter inverter assembly.

PROCEDURE

1. DTC OUTPUT (HV)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Read output DTCs. Hybrid Control System

Result:
The DTCs shown in the table below are output

YES -- GO TO DTC CHART
NO -- Continue to next step.
2. CHECK RELAY BLOCK ASSEMBLY
(a) Check the installation of the fusible links (DC/DC 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 CONNECTION CONDITION OF HYBRID VEHICLE CONTROL ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

(a) Check the connections of all HV control ECU connectors.
OK:
Connectors are connected securely and there is no poor connection.
NG -- CONNECT SECURELY
OK -- Continue to next step.
4. CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)
CAUTION: Be sure to wear insulated gloves.
(a) Turn the ignition switch off and remove the service plug grip. Hybrid Control System

NOTE: Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.
(b) Remove the inverter cover. Components

NOTICE:
- Wrap the interlock round terminal for the inverter cover with vinyl tape to prevent it from shorting to ground.
- Prevent water in the reservoir 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.

(c) Check the connections of the MG ECU connectors.
Standard:
Connectors are connected securely and there is no poor connection.
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 removed.

(b) Using a megohmmeter, 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 with the three-phase AC cable of the Motor connected.

NG -- INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR AND GENERATOR)
OK -- Continue to next step.
6. CHECK CONNECTION OF AMD TERMINAL
CAUTION: Be sure to wear insulated gloves.

(a) Check that the service plug grip is removed.

(b) Remove the three-phase AC cable for the Rear Motor from the w/ converter inverter assembly.
(c) Check the connection of the AMD terminal.
OK:
Terminal is connected securely and there is no poor connection.
NG -- CHECK AMD TERMINAL
OK -- Continue to next step.
7. CHECK AMD TERMINAL VOLTAGE (W/ CONVERTER INVERTER ASSEMBLY SIDE)
CAUTION: Be sure to wear insulated gloves.
(a) Turn the ignition switch off.
(b) Check that the service plug grip is removed.

NG -- CHECK AMD TERMINAL (VEHICLE SIDE)
OK -- Continue to next step.
8. INSPECT MG ECU
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is removed.
(b) Turn the ignition switch to the ON position.
NOTE: Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.
HINT: Turning the ignition switch to the ON position 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 HV CONTROL ECU)
(a) Turn the ignition switch off.
(b) (b) Disconnect the I21 connector from the MG ECU.

NG -- INSPECT HYBRID VEHICLE CONTROL ECU
OK -- Continue to next step.
10. CHECK OPERATION 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. Components

(c) Install the service plug grip.
(d) Put the vehicle into the READY-on state 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. (*1)
(f) Measure the auxiliary battery voltage according to the previous conditions (*1).
Standard Current and Voltage:

OK -- CHECK QUANTITY OF COOLANT (FOR INVERTER)
NG -- REPLACE W/ CONVERTER INVERTER ASSEMBLY
11. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR AND GENERATOR)
CAUTION: Be sure to wear insulated gloves.

(a) Check that the service plug grip is removed.
(b) Disconnect the three-phase AC cables of the HV transaxle assembly (Motor and Generator) from the w/ converter inverter assembly.

(c) Using a megohmmeter, 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.
12. INSPECT REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY
CAUTION: Be sure to wear insulated gloves.

(a) Check that the service plug grip is removed.
(b) Disconnect the three-phase AC cable for the Rear Motor from the w/ converter inverter assembly.

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

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

NG -- REPLACE W/ CONVERTER INVERTER ASSEMBLY
OK -- CONNECT SECURELY
14. CHECK QUANTITY OF COOLANT (FOR INVERTER)
(a) Check the coolant level.
OK:
There is a sufficient amount of coolant.
NG -- CHECK FOR COOLANT LEAKS AND ADD COOLANT (FOR INVERTER)
OK -- Continue to next step.
15. CHECK COOLANT HOSE

(a) Check if the hoses of the cooling system are not bent or clogged.
OK:
The hoses of the cooling system are not bent or clogged.
NG -- CORRECT TO NORMAL CONDITION
OK -- Continue to next step.
16. CHECK CONNECTION CONDITION OF WATER PUMP CONNECTOR (LOOSENESS AND POOR CONTACT)

(a) Check the connection of the water pump w/ motor & bracket assembly connector.
OK:
Connector is connected securely and there is no poor connection.
NG -- CONNECT SECURELY
OK -- Continue to next step.
17. PERFORM ACTIVE TEST BY TECHSTREAM (WATER PUMP)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(d) During the "Activate the Water Pump" active test, check operation of the water pump.
OK:
There are ripples in the reservoir tank coolant.
HINT: The water pump is also activated in the READY-on state.

NG -- INSPECT WATER PUMP W/ MOTOR & BRACKET ASSEMBLY CIRCUIT
OK -- Continue to next step.
18. PERFORM ACTIVE TEST BY TECHSTREAM (COOLING FAN)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.
(d) Perform the "Control the Electric Cooling Fan" active test.
OK:
Electrical cooling fan operate.
NG -- CHECK COOLING FAN CIRCUIT
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
19. CHECK AMD TERMINAL (VEHICLE SIDE)

(a) Turn the ignition 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 W/ CONVERTER INVERTER ASSEMBLY
20. INSPECT HYBRID VEHICLE CONTROL ECU

(a) Turn the ignition switch off and disconnect all HV 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 W/TRANSAXLE ASSEMBLY
CAUTION: Be sure to wear insulated gloves.

(a) Check that the service plug grip is removed.
(b) Disconnect the frame wire No.3 (three-phase AC cable for Rear Motor) from the rear traction motor w/ transaxle assembly.

NOTE: Wrap terminals U, V, and W of the frame wire No.3 (three-phase AC cable for Rear Motor) on the w/ converter inverter assembly side with insulation tape to prevent the terminals from contacting the ground.

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