The reasons for storing the diagnostic code P0894 OBD2 are
The transmission fluid level may be too low.
There may be internal damage to the transmission.
Perhaps the Transmission Rate Sensor (TSS) is defective.
TSS Sensor electrical circuit components may be defective.
Possible solutions of the DTC code P0894 Generic
The steps to solve the failures related to the DTC code P0894 OBDII are the following:
Check both the level and the state of the transmission fluid are required for the accurate operation of the system. Take into account if there is an excessively low level, it may be due to leaks. Also, if the fluid shows signs of burning, it will be necessary to replace it completely next to the filter. Make the necessary corrections.
With a digital volt-ohm meter test the reference, signal, and ground voltage of the Transmission Rate Sensor (TSS). Compare the results with the manufacturer's specifications. Repair as necessary.