DTC C1620: ECU Incorrect Attachment

PROBABLE CAUSES

caution

If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

OPERATION

ABS-ECU receives the vehicle information stored in the ETACS-ECU via CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS

ABS-ECU communicates with ETACS-ECU via CAN bus lines. This diagnosis code is set when the vehicle information received from the ETACS-ECU is invalid.

PROBABLE CAUSES

The hydraulic unit for 2WD vehicles (integrated with ABS-ECU) is installed on 4WD vehicles accidentally.
Malfunction of the hydraulic unit (integrated with ABS-ECU)
Malfunction of the ETACS-ECU