International SA 33 SPN 70 FMI 7: Air Powered Park Brake is stuck

SA 33 SPN 70 FMI 7 on International / Navistar trucks means: Air Powered Park Brake is stuck. The failure mode (FMI 7) is “mechanical system not responding or out of adjustment”.

Code details

Manufacturer: International (Navistar)
Applies to: International / Navistar body controller (ESC) and multiplexed modules
Fault code: SA 33 SPN 70 FMI 7
J1939 SPN: 70
FMI: 7 — Mechanical system not responding or out of adjustment
Reporting module: Body Controller (source address 33)
Component / signal: Air Powered Park Brake
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: Mechanical system not responding or out of adjustment

Occurs when the park brake switch does not match the spring apply-air release (SAAR) chamber travel sensor. This indicates the park brake cannot be applied or cannot be released.

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 7 tells the shop the type of failure to test for: mechanical system not responding or out of adjustment.
Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.