DTC P0A81-11: Hybrid/EV Battery Cooling Fan 1 Circuit Short to Ground; DTC P0A81-4B: Hybrid/EV Battery Cooling Fan 1 Over Temperature [11/2020 - 12/2022]: Description

The battery cooling blower assembly speed is controlled by the battery ECU assembly. The power source of the battery cooling blower assembly is supplied by turning the IGCT No. 2 relay and BATT FAN relay ON by the MREL terminal of the EV control ECU. 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 EV battery temperature. The frequency (FP0) of the battery cooling blower assembly is sent to the battery ECU assembly as a monitor signal.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	DTC Output from	Priority
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). (2 trip detection logic)	Battery cooling blower assembly Battery ECU assembly BATT FAN fuse Wire harness or connector	Master Warning: Comes on	EV Battery	A
P0A81-4B	Hybrid/EV Battery Cooling Fan 1 Over Temperature	Both of the following conditions are met: The EV battery temperature is high and the speed calculated based on the battery cooling blower assembly output frequency is not within the target control speed range. The EV battery temperature is high and 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	Master Warning: Comes on	EV Battery	A

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
P0A81-4B

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.