Deutz Fault Code
Free · no signupSPN 523470 FMI 2
Low power; Engine in limp mode; Rail pressure erratic.
System
Not specified
Symptom
Low power; Engine in limp mode; Rail pressure erratic.
Diagnosis & fix steps
Pressure Relief Valve (PRV) Fault
LOGIC: The PRV has "tripped" too many times or is leaking internally.
ACTION: Check the "PRV Opening Count" in the ECM. Check for fuel returning from the PRV line at idle.
FIX: Replace the Fuel Pressure Relief Valve and reset the PRV counter in the software.
Red Seal field insights
You cannot just replace the valve; you must reset the software counter, or the engine will stay in a "protection derate."
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
Track this across your whole fleet
This code is free to read. AM Fleet Integrity lets your team log fault codes against assets, plus the full fault-code library, QR operator reporting, PM scheduling and predictive alerts. Start free — no credit card required.
Start your free trialRelated Deutz fault codes
- SPN 523612 FMI 12Engine won't start; No communication with scanner; Dash says "No Engine Data."
- SPN 168 FMI 1Starter clicks; Gauges dimming; ECM resets; Random fault codes.
- SPN 639 FMI 9Total machine freeze; All gauges "X" out; Engine won't start.
- SPN 157 FMI 1Hard starting; Misfiring under load; Sudden engine stalling.
- SPN 651 FMI 5Engine knocking or "missing"; Significant vibration; Power loss.
- SPN 110 FMI 0Overheating; Engine power loss; High-speed fan active.
- SPN 91 FMI 3Engine stuck at idle; No throttle response; Service lamp on.
- SPN 102 FMI 2Turbo surge; Black smoke; Poor acceleration; Derate.
- SPN 97 FMI 3Water in Fuel lamp on; Potential derate to protect injectors.
- SPN 100 FMI 1Low oil pressure alarm; Engine derate; Potential shutdown.