International SA 33 SPN 520711 FMI 5: Humphrey Valve Primary Tank Solenoid Under Current Or Open Circuit

SA 33 SPN 520711 FMI 5 on International / Navistar trucks means: Humphrey Valve Primary Tank Solenoid Under Current Or Open Circuit. The failure mode (FMI 5) is “current below normal or open circuit”.

Code details

Manufacturer: International (Navistar)
Applies to: International / Navistar body controller (ESC) and multiplexed modules
Fault code: SA 33 SPN 520711 FMI 5
J1939 SPN: 520711
FMI: 5 — Current below normal or open circuit
Reporting module: Body Controller (source address 33)
Component / signal: Primary Air Tank Drain Valve Actuator Command
Truck models in source: 3200, 4100, 4300, 4400, 7300, 7400, 7500, 7600, 7700, 8500, 8600, BE 200, CE Bus, CXT, DuraStar, LoneStar, MXT, ProStar, RXT, TranStar, WorkStar

Cause and when it sets

Cause: Current below normal or open circuit

What to do next

Read active and inactive codes with the OEM service tool (Diamond Logic Builder can clear previously active codes) and note the occurrence count.
FMI 5 tells the shop the type of failure to test for: current below normal or open circuit.
Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.