Eaton Fuller Advantage (2017) Fault Code: 76 PID: SPN: 639 FMI: 31 Neutral Coast Mode: Condition Exists

Overview:
When available and enabled, Neutral Coast Mode allows the transmission to disengage the driveline by pulling out of gear on slight downhill grades, where little to no engine power is required, when the vehicle is in cruise control and the transmission is in Drive Mode. Neutral Coast may refer to one of several different systems that control various elements of vehicle cruise control logic. The transmission controlled version is an Eaton proprietary logic where the transmission makes the decisions when the driveline should be engaged or disengaged. Engine/J1939 controlled systems use an engine or another vehicle ECU to determine the appropriate times to engage or disengage the driveline. Engine/J1939 controlled systems have several different variations and brand names based on the manufacturer. Fault Code 76 indicates that either the Transmission ECU or Engine/Vehicle ECU are mis-configured for use with a Neutral Coast system.

Detection:
Incorrect engine/vehicle or transmission configuration settings can set this fault. When the engine/vehicle and transmission configurations are not matched for use with Neutral Coast systems, this fault will set Active.

Conditions to Set Fault Code Active:
• FMI 31 – Condition Exists: Engine or vehicle configurations and/or software are incorrectly set for use with a Neutral Coast system.

Fallback:
All FMIs: Neutral Coast systems will not function.

Conditions to Set Fault Code Inactive:
All FMIs: This fault is set inactive when the transmission and engine/vehicle Neutral Coast system configurations or software are correctly set.

Possible Causes:
FMI 31
1) Engine ECM
– Incorrect engine software settings