Overview:
The Fuller Advantage transmission is equipped with an Electric Clutch Actuator (ECA) that controls the position of the clutch assembly. The ECA operates on a non-switched battery power supply. Fault Code 66 indicates battery power to the ECA is outside of the acceptable ECA operating range.

Detection:
ECA monitors the battery voltage supply it receives. If the supplied voltage falls below operating range or spikes significantly above operating range, the ECA will broadcast a fault condition to the TECU, which sets the fault code Active.

Conditions to Set Fault Code Active:
FMI 3 – Voltage Above Normal or Shorted High: ECA battery voltage rises above 34 volts for 2 seconds or longer.

Fallback:
All FMIs
• “F” flashes in gear display.
• Service light flashes (if equipped).
• Engine does crank and/or start.
• Transmission does not engage a gear from neutral.
• When the transmission is in gear, it will not allow up shifts.
• ECA may maintain the current clutch position using the clutch holding device.
• ECA may move the clutch to the closed position (clutch engaged against engine flywheel).

Conditions to Set Fault Code Inactive:
FMI 3: ECA battery voltage drops below 32 volts for 6 seconds.

Possible Causes:
FMI 3
1) Starting/Charging System
– Alternator/Generator failure
– Improper vehicle jump-start