DTC P0A81-11: Hybrid/EV Battery Cooling Fan 1 Circuit Short to Ground [08/2020 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, and 2021 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

The battery cooling blower assembly speed is controlled by the battery ECU assembly. Power is supplied to the battery cooling blower assembly when the MREL terminal of the hybrid vehicle control ECU turns on the IGCT relay. The battery ECU assembly sends command signals (SI0) to the battery cooling blower assembly to adjust the fan speed to an appropriate speed for the HV battery temperature. The frequency (FP0) of the battery cooling blower assembly is sent to the battery ECU assembly as a monitor signal.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P0A81-11	Hybrid/EV Battery Cooling Fan 1 Circuit Short to Ground	Both of the following conditions are met: The speed calculated based on the battery cooling blower assembly output frequency is not within the target control speed range. The battery cooling blower assembly speed is excessively low when a certain level of speed is requested (possibility of an open or short to ground in connected circuits, or motor locking). (1 trip detection logic)	Battery cooling blower assembly Battery ECU assembly BATT FAN fuse Wire harness or connector	Comes on	Master Warning Light: Comes on

RELATED DATA LIST

DTC No.	Data List
P0A81-11	Hybrid/EV Battery Cooling Fan 1 Drive Request Hybrid/EV Battery Cooling Fan 1 Drive Status Hybrid/EV Battery Cooling Fan 1 Frequency

The following items can be helpful when performing repairs:

Data List

Hybrid/EV Battery Temperature 1 to 6
BATT Voltage

HINT:

"Hybrid/EV Battery Cooling Fan 1 Frequency" is detected when the battery cooling blower assembly is operating and its value changes in proportion to the battery cooling blower assembly speed.