TriPac APU 3rd Generation Codes

This APU came to market in 2023.

Code 63. Engine stopped. Usually problems with fuel supply. Or air coming into the system. Check fuel filter tightness 

Code 93 (Low Pressure Cutout or LPCO). If refrigerant pressure is abnormally low (2 psig +/- 2) the normally closed switch contacts will open to signal the Controller. It removes power from the compressor clutch. Check refrigerant in the system.

Code 10 (High Discharge Pressure or HPCO). If the refrigerant pressure becomes abnormally high (400 psig) the normally closed switch contacts will open to signal the Controller. It removes power from the
compressor clutch. When refrigerant pressure returns to normal the normally closed HPCO contacts will close. If cooling is still required power is applied to the compressor clutch and starts the compressor.

Code 19 (Low Engine Oil Pressure or Oil Pressure). This normally closed switch opens when oil pressure rises above 15 psi. The switch itself may be bad. 

Code Low RPM: Adjust RPMs to 2,400-2,500 range 

Code 155. Lost CAN communication with HMI. Unplug HMI (controller on the wall inside the cab) and plug back.

Code 288. Lost CAN communication with RIO.

Replace the A288 modulator box out, This is a electronic circuit that superimposes a low frequency (it's a wireless connection box). On motherboard.

Code A68 (lost communication). Needs a quick software update from the dealership  

See a list of Codes for TriPac Evolution (2nd generation).

For Exhaust After Treatment Codes see this article.