DTC P1CCC-96: DC/DC Converter Enable Component Internal Failure [12/2023 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.

The DC/DC converter converts the DC 355.2 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 355 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 hybrid vehicle control ECU assembly 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 hybrid vehicle control ECU assembly 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 ignition switch to ON (READY).

If a DC/DC converter malfunction occurs, DC/DC converter malfunction signals are sent from the DC/DC converter to the hybrid vehicle control ECU assembly 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.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	DTC Output from	Priority	Note
P1CCC-96	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 DC/DC converter is malfunction for 5 seconds. (1 trip detection logic)	No. 1 luggage room relay block and No. 1 junction block assembly Hybrid vehicle control ECU assembly DC/DC converter cooling system Cooling fan system DC/DC converter assembly No. 1 junction block assembly DC/DC fuse Floor under wire No. 1 high voltage socket inverter wire	Does not come on	Master Warning: Comes on	Hybrid Control	A	SAE Code: P1CCC

HINT:

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