Overview:
The Fuller Advantage transmission is equipped with a Transmission Electronic Control Unit (TECU). The TECU performs a variety of functions including receiving inputs from sensors, sending outputs to control devices, operating X-Y Shifter motors and actuators and making shift decisions. Fault Code 12 indicates an internal failure of the TECU.

Detection:
The TECU performs a self-check during power up. If the TECU does not detect valid memory, or if there are missing or corrupt transmission configuration files, this fault sets Active.

Conditions to Set Fault Code Active:
FMI 13 – Out of Calibration: TECU is unable to determine the proper transmission configuration.

Fallback:
FMI 13
• “F” flashes in gear display.
• Service light flashes (if equipped).
• Engine may not crank.
• Transmission may not engage a gear.
• Transmission may not make up shifts or down shifts.
• Engine may have to be shut down with transmission still in gear.

Conditions to Set Fault Code Inactive:
FMI 13: TECU has detected a proper configuration for the transmission.

Possible Causes:
1) TECU
2) Internal failure