Eaton Fuller Advantage (2017) Fault Code: 66 PID: SPN: 520271 FMI: 4 ECA Battery Voltage: Voltage Below Normal or Shorted Low

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 4 – Voltage Below Normal or Shorted Low: ECA battery voltage falls below 8.5 volts for 2 seconds or longer and the TECU has not detected low or weak battery voltage.

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 4: ECA battery voltage rises above 9 volts on 12-volt chassis or above 18 volts on 24-volt chassis for 6 seconds

Possible Causes:
FMI 4
1) ECA Vehicle Harness
– Damaged wiring between the vehicle batteries and 3-Way ECA Connector
– Bent, spread, corroded or loose terminals
– Wiring shorted to ground, shorted to power or open
2) ECA 40-amp Fuse
– Bent, spread, corroded or loose fuse terminals
– Fuse not properly seated or connected
3) Vehicle Batteries
– Internal failure
4) Starting/Charging System
– Alternator/Generator failure
5) ECA
– Internal failure