SPN 1569 FMI 31 — Engine Protection — Power Derate Active
What it means: A general engine-protection derate is active.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Read the COMPANION active codes — SPN 1569 alone won't tell you the trigger; the partner code will.
Don't risk it — look up listed providers near you and give them this SPN/FMI when you call.
Listed providers nearest Albuquerque, NM
Closest first. Tell them SPN 1569 FMI 31 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Albuquerque, NM · (505) 226-2125
- 0.0 mi away — based in Albuquerque, NM · (505) 823-9696
- 0.0 mi away — based in Albuquerque, NM · (505) 220-3541
What SPN 1569 FMI 31 means
A general engine-protection derate is active. The ECM has pulled power to protect the engine because another monitored parameter — coolant temp, oil pressure, aftertreatment, or boost — is out of range. SPN 1569/FMI 31 tells you a derate is on; it does not by itself say why.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Aftertreatment fault (DPF/DEF/SCR) commanding a derate
- High coolant temperature or low coolant level
- Low oil pressure protection
- Boost/turbo or intake-air fault the ECM is guarding against
First moves (roadside)
- Read the COMPANION active codes — SPN 1569 alone won't tell you the trigger; the partner code will.
- Check the dash: coolant temp, oil pressure, and DEF/check-engine lamps.
- If gauges are normal, suspect an aftertreatment-driven derate and inspect for DPF/DEF codes.
- Don't keep pushing a derated truck under load — it can escalate to a no-start or engine damage.
Common misdiagnoses
- Treating 1569 as the root cause instead of reading the companion fault that triggered it.
- Assuming it's always emissions — overheating and low oil pressure trigger the same derate flag.
- Clearing the derate without addressing the underlying parameter that's out of range.
FAQ
A general engine-protection derate is active. The ECM has pulled power to protect the engine because another monitored parameter — coolant temp, oil pressure, aftertreatment, or boost — is out of range. SPN 1569/FMI 31 tells you a derate is on; it does not by itself say why.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Aftertreatment fault (DPF/DEF/SCR) commanding a derate. Other possibilities include High coolant temperature or low coolant level; Low oil pressure protection; Boost/turbo or intake-air fault the ECM is guarding against.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside SPN 1569 FMI 31, or share the same subsystem.
- Intake Manifold (Charge Air) Temp — High (SPN 105 FMI 0)
- Turbo Boost Pressure — High / Overboost (SPN 1127 FMI 16)
- Boost pressure high (SPN 102 FMI 0)
- Boost sensor — voltage low (SPN 102 FMI 4)
- Intake manifold temp — voltage high (SPN 105 FMI 3)
- Intake manifold temp — voltage low (SPN 105 FMI 4)
- Injection control pressure low (HEUI — older engines) (SPN 164 FMI 1)
- Fuel temperature high (SPN 174 FMI 16)
Same symptom: Low oil pressure
Other codes a driver sees as an oil-pressure or oil-level warning.
- Engine Oil Pressure — Extremely Low (SPN 100 FMI 1) · Lubrication
- Engine Oil Pressure Too Low (P0524) · Lubrication
- Oil pressure sensor — voltage high (SPN 100 FMI 3) · Lubrication
- Oil pressure sensor — voltage low (SPN 100 FMI 4) · Lubrication
- Trans oil pressure voltage high (SPN 1762 FMI 3) · Drivetrain & Transmission
- Trans oil pressure voltage low (SPN 1762 FMI 4) · Drivetrain & Transmission
Find a mechanic or related guides
General diagnostic guidance for heavy-duty diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack). Not a substitute for a scan-tool diagnosis on your specific truck.