International SA 23 SPN 1727 FMI 4: Fault on Analog Input 1 below normal when used for axle load

SA 23 SPN 1727 FMI 4 on International / Navistar trucks means: Fault on Analog Input 1 below normal when used for axle load. The failure mode (FMI 4) is “voltage below normal, or shorted to low source”.

Code details

Manufacturer: International (Navistar)
Applies to: International / Navistar body controller (ESC) and multiplexed modules
Fault code: SA 23 SPN 1727 FMI 4
J1939 SPN: 1727
FMI: 4 — Voltage below normal, or shorted to low source
Reporting module: Electronic Gauge Cluster (EGC) (source address 23)
Component / signal: Rear Axle Below Pressure
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: Voltage below normal, or shorted to low source

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 4 tells the shop the type of failure to test for: voltage below normal, or shorted to low source.
Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.