P0A09-591

P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A09-591: DC / DC Converter Status Circuit Low Input

DTC P0A09-591 - DC / DC Converter Status Circuit Low Input

DTC P0A10-592 - DC / DC Converter Status Circuit High Input

DESCRIPTION

The DC / DC converter converts the DC 201.6 V of the HV battery into DC 12 V in order to supply power to 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 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.

The HV control ECU sends the output voltage switch signal to the DC / DC converter via the VLO signal line in order to switch output voltage according to vehicle status.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FUSIBLE LINK BLOCK (100A DC/DC)
(a) Disconnect the battery negative terminal.

(b) Measure the resistance of the DC/DC fuse.
Standard resistance:
Below 1 Ohms
NG -- CHECK INVERTER WITH CONVERTER ASSEMBLY (AMD TERMINAL)
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - DC / DC CONVERTER)
(a) Connect the battery negative terminal.
(b) Disconnect the H16 HV control ECU connector.

(e) Measure the voltage between the terminal of the HV control ECU connector and body ground.
Standard voltage:

(f) Turn the power switch OFF.

(g) Measure the resistance between the wire harness side connectors.
Standard resistance (Check for open):

Standard resistance (Check for short)

(h) Reconnect the DC / DC converter connector.
(i) Reconnect the HV control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
3. CHECK INVERTER WITH CONVERTER ASSEMBLY (AMD TERMINAL)
(a) Disconnect the battery negative terminal.
(b) Disconnect the C6 connector.

(c) Measure the resistance between the C6 connector terminal of the inverter with converter assembly and body ground.
Standard resistance:

(d) Connect the C6 connector.
NG -- REPLACE INVERTER WITH CONVERTER ASSEMBLY AND FUSIBLE LINK BLOCK (DC/DC FUSE)
OK -- REPLACE FUSIBLE LINK BLOCK (DC/DC FUSE) AND REPAIR THE SHORT CIRCUITS