International SA 33 SPN 1087 FMI 0: Primary Air Tank Sensor reading above normal range

SA 33 SPN 1087 FMI 0 on International / Navistar trucks means: Primary Air Tank Sensor reading above normal range. The failure mode (FMI 0) is “data valid but above normal operating range (most severe)”.

Code details

Manufacturer: International (Navistar)
Applies to: International / Navistar body controller (ESC) and multiplexed modules
Fault code: SA 33 SPN 1087 FMI 0
J1939 SPN: 1087
FMI: 0 — Data valid but above normal operating range (most severe)
Reporting module: Body Controller (source address 33)
Component / signal: Service Brake Air Pressure Circuit #1
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
Connector pins: 1600-B2
Logical signal: Primary_Air_Sensor_Raw_Si gnal

Cause and when it sets

Cause: Primary Air Tank Sensor Shorted High or faulty sensor system

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 0 tells the shop the type of failure to test for: data valid but above normal operating range (most severe).
Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.