Caterpillar Fault Code
Free · no signupE001 (Level 2)
Power Derate (Limiting RPM).
System
Cooling
Symptom
Power Derate (Limiting RPM).
Diagnosis & fix steps
LOGIC: Coolant temp has hit the "Action" threshold (approx. 107°C / 225°F).
ACTION: The ECM will cut fuel to protect the head. Check coolant level and fan belt tension.
Red Seal field insights
Specs: ECM will reduce power by 25%.
RED SEAL FIX: Check the Thermostat (Regulator). CAT regulators have a rubber seal that can "roll," preventing the valve from opening fully.
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.
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