DTC P1CCC-96: DC/DC Converter Enable Component Internal Failure [10/2018 - ]: Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.

The DC/DC converter converts the DC 244.8 V of the HV battery into DC 12 V in order to supply power to areas such as the vehicle lighting system, audio system and various ECUs. Additionally, it charges the auxiliary battery.

A transistor bridge circuit initially converts DC 244.8 V into alternating current, and a transformer lowers the voltage.

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

Then, it is rectified and smoothed (into direct current) and converted into DC 12 V.

The motor generator control ECU sends a signal to the DC/DC converter to prohibit its control and receives signals indicating a normal or abnormal condition of the 12 V charging system via the NODD signal line.

If the DC/DC converter malfunctions, the vehicle will become inoperative. Therefore, the motor generator control ECU monitors the operation of the DC/DC converter and detects malfunctions.

This DTC is stored when the DC/DC converter circuit has a malfunction or its operation is prohibited by a fail-safe function, or the auxiliary battery voltage drops to 11 V or less with the power switch on (READY).

If a DC/DC converter malfunction occurs, DC/DC converter malfunction signals are sent from the DC/DC converter to the MG ECU via the NODD signal line.

This DTC may also be stored if a malfunction of the inverter cooling system (blockage, inverter water pump malfunction, etc.) or a high-voltage insulation malfunction occurs.

Fig 1: DC/DC Converter Enable Component Internal Failure Circuit Diagram

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P1CCC96	DC/DC Converter Enable Component Internal Failure	Both of the following conditions are met: The DC/DC converter is malfunctioning and the auxiliary battery voltage is 11 V or less.* The inverter coolant temperature is 70°C or lower for 60 seconds. (1 trip detection logic)	Fusible link block assembly Engine wire Inverter cooling system Cooling fan system Inverter with converter assembly Hybrid vehicle transaxle assembly Motor cable	Does not come on	Master Warning: Comes on

HINT:

*: If the DC/DC converter is malfunctioning, its operation and charging will be stopped and the auxiliary battery voltage will drop.