P1746

P0602
Control unit defective (watchdog)

P0603
Control unit (EEPROm)

P0605
Control unit (checksum)

P1746
Control unit defective (relay)

NOTE: If these faults are displayed, the transmission control unit is defective and must be replaced.

P1748
Control unit defective (relay sticks)

With this fault, first check the supply lead for the solenoid vales and pressure regulators for short circuit to B+ (see DTC 1750). If OK, replace Tiptronic control module.