P0A09 / INF265

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

DESCRIPTION

DTC Detection Condition:

The hybrid vehicle converter (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 hybrid vehicle 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 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 hybrid vehicle control ECU monitors the operation of the hybrid vehicle converter and alerts the driver if it detects a malfunction.

Wiring Diagram:

Step 1-3:

Step 3(Continued)-4:

Step 4(Continued):

Step 5:

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 10 minutes before touching any of the high-voltage connectors or terminals. After waiting, check the voltage at the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

HINT: Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.