DTC C1A15: Gear Position Signal Mismatch: Description

WARNING: This page is about a different car, the 2016 Infiniti QX80. However, it is still accessible from the selected car via links, so may be relevant.

ADAS control unit judges the gear position based on the following signals.

Current gear position signal transmitted from TCM via CAN communication.
Value of gear ratio calculated from input speed signal transmitted from TCM via CAN communication.
Value of gear ratio calculated from the vehicle speed signal transmitted from ABS actuator and electric unit (control unit) via CAN communication.