The check 4WD warning light illuminates when the ignition switch is turned ON, and then turns OFF after 3 seconds if a DTC is not set. The check 4WD warning light illuminates by TCCM sending light illumination requests to the instrument panel cluster via CAN communication.
Check 4WD warning light function
The check 4WD warning light is installed inside the instrument panel cluster and illuminates when a malfunction occurs in order to notify the driver that an inspection and repair must be performed as soon as possible. If the check 4WD warning light remains ON in response to a command from the TCCM, the DTC is set.
Check 4WD warning light illumination conditions