P0A10

P310 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A09-265: DC / DC Converter Status Circuit Low Input

DTC P0A09-265 - DC / DC Converter Status Circuit Low Input

DTC P0A10-263 - DC / DC Converter Status Circuit High Input

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 for 5 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.
HINT: Waiting for at least 5 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. 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.
2. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - MG ECU)
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.
(b) Disconnect the A43 connector from the hybrid vehicle control ECU.
(c) Disconnect the A42 connector from the MG ECU.





(d) Measure the voltage according to the value(s) in the table below.
NOTE: Turning the power switch on (IG) with the MG ECU connectors disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

Standard voltage:





(e) Turn the power switch off.
(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):






Standard resistance (Check for short):






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY