Caterpillar Fault Code
Free · no signupMID 036 CID 0544 FMI 08
Engine Coolant Temp Creep / High Roar
System
Cooling
Symptom
Engine Coolant Temp Creep / High Roar
Diagnosis & fix steps
LOGIC: Hydraulic Demand Fan Speed Sensor Frequency Abnormal.
ACTION: Remove Hall-effect speed pickup from the hydraulic fan motor casing. Clean metallic wear dust off the sensor tip and verify air gap to the internal target wheel (spec: 1.0 mm).
Red Seal field insights
Thermal Management: When the Engine ECM loses fan speed frequency feedback, it defaults the hydraulic demand pump to 100% displacement, draining ~30 HP and roaring continuously.
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 trial