115 Caterpillar diagnostic codes on file — with the full diagnosis, repair steps, and field insights open to read free, no signup required.
Disclaimer: General reference information for trained, qualified technicians only. Codes and procedures vary by model, serial number and software version. Always follow the manufacturer's service manual and your site's safety procedures. Use at your own risk. Not affiliated with or endorsed by any manufacturer.
| Code | System | Symptom | Full fix |
|---|---|---|---|
| 55 | C9 Flash Codes | No Codes Detected | View fix |
| 56 | C9 Flash Codes | Check System Parameters | View fix |
| 586-12 | Controls | Engine Speed Won't Change | View fix |
| 600-4 | Hydraulic | Hydraulic Temp Gauge High | View fix |
| 61 | C9 Flash Codes | High Coolant Temp | View fix |
| 62 | C9 Flash Codes | Low Coolant Level | View fix |
| 63 | C9 Flash Codes | Low Fuel Pressure | View fix |
| 64 | C9 Flash Codes | High Intake Air Temp | View fix |
| 65 | C9 Flash Codes | High Fuel Temperature | View fix |
| 71-76 | C9 Flash Codes | Cylinder #X Injector Fault | View fix |
| 735-6 | Hydraulic | Heavy Lift Solenoid: Current Above Normal | View fix |
| 735-6 | Hydraulic | Heavy Lift Locked / Noisy MCV | View fix |
| 92-95 | C9 Flash Codes | Intake Valve Actuator (IVA) | View fix |
| CA428 | Fuel | Water in Fuel lamp; Rough running. | View fix |
| CA689 | Engine | Engine Speed Sensor: Erratic Signal | View fix |
| CAT 171-3 (171-3) | Ambient | A/C Inop / High Idle. | View fix |
| Code 1301 | Lubrication | Engine Shutdown / Warning Alarm | View fix |
| Code 1301 | Lubrication | Engine Shutdown / Warning Alarm | View fix |
| Code 1301 | Lubrication | Engine Shutdown / Warning Alarm | View fix |
| E001 (Level 1) | Cooling | Warning on dash (No Derate). | View fix |
| E001 (Level 2) | Cooling | Power Derate (Limiting RPM). | View fix |
| E001 (Level 3) | Cooling | Immediate Shutdown Warning. | View fix |
| E1239 | Hydraulic | Heavy Lift Solenoid: Current Above Normal | View fix |
| E1239 | Hydraulic | Heavy Lift Weak / No Response | View fix |
| E1239 | Aftertreatment | 100% Derate / Forced Idle | View fix |
| E1389 FMI 3 | Emissions / SCR | Level 3 Inducement / Severe Engine Derate | View fix |
| E157-2 | Fuel System | Engine Stalling / High Load | View fix |
| E1729 FMI 03 | Emissions / DEF | AdBlue Warning / 5 MPH Limp Count | View fix |
| E360 | Engine | Low Oil Pressure Alarm | View fix |
| E361 | Engine | Engine Over-Speed Warning / Safety Trip | View fix |
| MID 027 CID 0368 FMI 02 | Transmission | Harsh Shifts / Transmission Slip | View fix |
| MID 036 CID 0100 FMI 01 | Lubrication | Level 3 Red Stop Light / Engine Derate | View fix |
| MID 036 CID 0168 FMI 01 | Electrical | Multiple Sensor Faults / Monitor Blinks | View fix |
| MID 036 CID 0544 FMI 08 | Cooling | Engine Coolant Temp Creep / High Roar | View fix |
| MID 036 CID 2265 FMI 03 | Fuel Supply | Engine Sags under Heavy Push / Stumble | View fix |
| MID 039 CID 0296 FMI 09 | Communication | VIMS Dash Blank / Shift Inhibited | View fix |
| MID 082 CID 0568 FMI 07 | Braking | Brake Warning / High Pedal Effort | View fix |
| MID 087 CID 0373 FMI 05 | Braking / Traction | Service Brakes Locked / Alarm Active | View fix |
| MID 087 CID 0420 FMI 05 | Electrical / Steering | Secondary Steering Active / Alarm | View fix |
| SPN 100 FMI 3 | — | Low oil pressure warning on dash; Possible engine derate; Gauge pinned to maximum or reading zero. | View fix |
| SPN 101 FMI 15 | Engine | Oil Leaking from Breather. | View fix |
| SPN 102 FMI 18 | Air Intake | Power Loss / Black Smoke | View fix |
| SPN 102 FMI 18 | Air Intake | Power Loss / Black Smoke | View fix |
| SPN 102 FMI 18 | Air Intake | Power Loss / Black Exhaust Smoke | View fix |
| SPN 102 FMI 3 | — | Low power; Excessive black smoke; Poor throttle response; "Lazy" turbo feel. | View fix |
| SPN 108 FMI 4 | — | Engine is "lazy"; Poor fuel economy; Struggles at high altitude. | View fix |
| SPN 1087 FMI 1 | Braking / Air | Brake Pressure Warning / Truck Derate | View fix |
| SPN 111 FMI 1 | — | Warning light/Buzzer; Engine shutdown protection active; Potential coolant spray. | View fix |
| SPN 1569 FMI 31 | Engine Control | Engine Protection Derate. | View fix |
| SPN 1569 FMI 31 | Engine Control | Engine Derate (Power Loss) | View fix |
Same codes keep 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.
AM Fleet Integrity gives you QR-code operator reporting, preventive maintenance scheduling, and predictive alerts in one place. Start your 14-day free trial — no credit card required.
Start your free trial