Diagnostics
CAT Engine Fault Codes: Meanings, Causes & Fixes
In-depth, plain-English guides to CAT Engine fault codes and error codes. Each guide covers what the code means, what triggers it, the most common causes, and the first things to check before you call the dealer.
- 10010Engine Oil Pressure Sensor abnormal rate of change
- 10013Engine Oil Pressure calibration required
- 1003Engine Oil Pressure open/short to +batt
- 1004Engine Oil Pressure short to ground
- 10113Crankcase Air Pressure Sensor:Calibration Required
- 1013Crankcase Air Pressure Sensor : Voltage Above Normal
- 1014Crankcase Air Pressure Sensor : Voltage Below Normal
- 105Cylinder #10 Injector : Current Below Normal
- 106Cylinder #10 Injector : Current Above Normal
- 10765Engine Cooling Fan Bypass Solenoid open circuit
- 10766Engine Cooling Fan Bypass Solenoid short to ground
- 1103Engine Coolant Temperature open/short to +batt
- 1104Engine Coolant Temperature short to ground
- 111Cylinder #1 Injector fault
- 115Cylinder #11 Injector : Current Below Normal
- 116Cylinder #11 Injector : Current Above Normal
- 12Cylinder #1 Injector : Erratic, Intermittent, or Incorrect
- 125Cylinder #12 Injector : Current Below Normal
- 126Cylinder #12 Injector : Current Above Normal
- 15Cylinder #1 Injector : Current Below Normal
- 157Low Engine Oil Pressure - Warning
- 15893Turbo Inlet Air Pressure Sensor Open/Short to +Batt
- 15894Turbo Inlet Air Pressure Sensor Short to Ground
- 16Cylinder #1 Injector short
- 16275Fuel Pump Relay:Current Below Normal
- 16276Fuel Pump Relay:Current Above Normal
- 16392Machine Security System Incorrect
- 16399Machine Security System Module : Abnormal Update Rate
- 16411Injector Actuation Pressure system fault
- 1643Injector Actuation Pressure Voltage High
- 1644Injector Actuation Pressure Voltage Low
- 168High Engine Coolant Temperature - Derate
- 1680System Voltage High
- 1681System Voltage Low
- 1682System Voltage intermittent/erratic
- 1684Electrical System Voltage : Voltage Below Normal
- 17Cylinder #1 Injector : Not Responding Properly
- 1723Intake Manifold Air Temp open/short to +batt
- 1724Intake Manifold Air Temp short to ground
- 1743Fuel Temperature open/short to +batt
- 1744Fuel Temperature short to ground
- 1753Engine Oil Temperature open/short to +batt
- 1754Engine Oil Temperature short to ground
- 178510Intake Manifold Pressure Signal Abnormal Rate of Change
- 178513Intake Manifold Pressure Sensor : Calibration Required
- 178521Intake Manifold Pressure Sensor : Data Drifted Low
- 17853Intake Manifold Pressure Sensor : Voltage Above Normal
- 17854Intake Manifold Pressure Sensor : Voltage Below Normal
- 179710Fuel Rail Pressure Sensor : Abnormal Rate of Change
- 17973Fuel Rail Pressure Sensor : Voltage Above Normal
- 17974Fuel Rail Pressure Sensor : Voltage Below Normal
- 1811Fuel Control Valve : Other Failure Mode
- 1812Fuel Control Valve: Failure
- 18342Ignition Key Switch loss of signal
- 187Fuel Control Valve : Not Responding Properly
- 19011Engine Speed Sensor mechanical failure
- 1902Loss of Engine Speed Signal
- 1903Engine Speed Sensor Voltage Above Normal
- 1908Engine Speed signal abnormal
- 211Cylinder #2 Injector fault
- 213135 Volt Sensor DC Power Supply #2 : Voltage Above Normal
- 213145 Volt Sensor DC Power Supply #2 : Voltage Below Normal
- 22Cylinder #2 Injector : Erratic, Intermittent, or Incorrect
- 22466Engine Glow Plug Relay : Current Above Normal
- 24175Ether Injection Control Solenoid : Current Below Normal
- 24176Ether Injection Control Solenoid : Current Above Normal
- 2479SAE J1939 Data Link : Abnormal Update Rate
- 2489Cat Data Link not communicating
- 25Cylinder #2 Injector open circuit
- 2532Personality Module : Erratic, Intermittent, or Incorrect
- 25335Compression Brake Low/High Solenoid #1 : Current Below Normal
- 25336Compression Brake Low/High Solenoid #1 : Current Above Normal
- 25345Compression Brake Low/High Solenoid #2 current below normal
- 25346Compression Brake Low/High Solenoid #2 current above normal
- 25355Compression Brake Medium/High Solenoid #1 : Current Below Normal
- 25356Compression Brake Medium/High Solenoid #1 : Current Above Normal
- 25365Compression Brake Medium/High Solenoid #2 current below normal
- 25366Compression Brake Medium/High Solenoid #2 current above normal
- 25412Electronic Control Module Error
- 26Cylinder #2 Injector : Current Above Normal
- 26025Cylinder #1 Injector Actuator #2:Current Below Normal
- 26026Cylinder #1 Injector Actuator #2:Current Above Normal
- 26045Cylinder #2 Injector Actuator #2:Current Below Normal
- 26046Cylinder #2 Injector Actuator #2:Current Above Normal
- 26065Cylinder #3 Injector Actuator #2:Current Below Normal
- 26066Cylinder #3 Injector Actuator #2:Current Above Normal
- 26085Cylinder #4 Injector Actuator #2:Current Below Normal
- 26086Cylinder #4 Injector Actuator #2:Current Above Normal
- 26105Cylinder #5 Injector Actuator #2:Current Below Normal
- 26106Cylinder #5 Injector Actuator #2:Current Above Normal
- 26111Engine Timing Offset fault
- 26113Engine Timing Calibration required
- 26125Cylinder #6 Injector Actuator #2:Current Below Normal
- 26126Cylinder #6 Injector Actuator #2:Current Above Normal
- 26235 Volt Sensor DC Power Supply short to +batt
- 26245 Volt Sensor DC Power Supply short to ground
- 2633Digital Sensor Supply short to +batt
- 2634Digital Sensor Supply short to ground
- 2648Decel Throttle Position Signal Abnormal
- 2672Incorrect Engine Shutdown Switch inputs
- 2673Remote Shutdown Input : Voltage Above Normal
- 2674Remote Shutdown Input : Voltage Below Normal
- 2682Programmed Parameter Fault : Erratic, Intermittent, or Incorrect
- 27Cylinder #2 Injector : Not Responding Properly
- 273Turbo Outlet Pressure above normal
- 27313Turbo Outlet Pressure calibration required
- 2733Turbo Outlet Pressure open/short to +batt
- 2734Turbo Outlet Pressure short to ground
- 27383Turbocharger #1 Compressor Inlet Pressure Sensor : Voltage Above Normal
- 27384Turbocharger #1 Compressor Inlet Pressure Sensor : Voltage Below Normal
- 27413Atmospheric Pressure Sensor: Calibration Required
- 2743Atmospheric Pressure open/short to +batt
- 2744Atmospheric Pressure short to ground
- 27513Right Turbo Inlet Pressure calibration required
- 2753Right Turbo Inlet Pressure open/short to +batt
- 2754Right Turbo Inlet Pressure short to ground
- 27703Throttle Lock Resume/Decel Switch Voltage Above Normal
- 27704Throttle Lock Resume/Decel Switch : Voltage Below Normal
- 27713Throttle Lock Set/Accel Switch : Voltage Above Normal
- 27714Throttle Lock Set/Accel Switch Voltage Below Normal
- 2835Filter Restrict Lamp open/short to +batt
- 2836Filter Restrict Lamp short to ground
- 2915Engine Cooling Fan Solenoid open circuit
- 2916Engine Cooling Fan Solenoid short to ground
- 2969Unable to communicate with Transmission ECM
- 311Cylinder #3 Injector fault
- 32Cylinder #3 Injector : Erratic, Intermittent, or Incorrect
- 32011Speed/Timing Sensor Mechanical Failure
- 3202Speed/Timing Sensor Loss of Signal
- 34211Secondary Engine Speed Sensor mechanical failure
- 3422Loss of Secondary Engine Speed signal
- 3428Secondary Engine Speed Sensor : Abnormal Frequency, Pulse Width, or Period
- 35Cylinder #3 Injector : Current Below Normal
- 36Cylinder #3 Injector : Current Above Normal
- 360912Aftertreatment #1 Outlet #1 NOx Level Sensor : Failure
- 37Cylinder #3 Injector : Not Responding Properly
- 38215Aftertreatment #1 Diesel Exhaust Fluid Dosing Valve Actuator : Current Below Normal
- 411Cylinder #4 Injector fault
- 4138 Volt DC Supply short to +batt
- 4148 Volt DC Supply short to ground
- 42Cylinder #4 Injector : Erratic, Intermittent, or Incorrect
- 425Injector Actuation Valve Open Circuit
- 426Injector Actuation Valve Short to Ground
- 45Cylinder #4 Injector : Current Below Normal
- 46Cylinder #4 Injector : Current Above Normal
- 4603Fuel Pressure Sensor - After Fuel Filter : Voltage Above Normal
- 4604Fuel Pressure Sensor - After Fuel Filter : Voltage Below Normal
- 47Cylinder #4 Injector : Not Responding Properly
- 4855Engine Fan Rev Solenoid Open Circuit
- 4856Engine Fan Rev Solenoid Short to Ground
- 511Cylinder #5 Injector fault
- 52Cylinder #5 Injector : Erratic, Intermittent, or Incorrect
- 5448Engine Cooling Fan Speed signal abnormal
- 5455Ether Start Relay open/short to +batt
- 5456Ether Start Relay short to ground
- 5465Ether Hold Relay open/short to ground
- 5466Ether Hold Relay short to +batt
- 5485Throttle Lock Lamp open circuit
- 5486Throttle Lock Lamp short
- 5492Incorrect Throttle Lock Switch inputs
- 55Cylinder #5 Injector open circuit
- 56Cylinder #5 Injector short
- 5629Unable to Communicate with Cat Monitoring System
- 57Cylinder #5 Injector : Not Responding Properly
- 58569SAE J1939 Data Link #3:Abnormal Update Rate
- 611Cylinder #6 Injector fault
- 6176Air Inlet Heater Relay Grounded/Current Above Normal
- 62Low Engine Coolant Level Shutdown
- 65Cylinder #6 Injector : Current Below Normal
- 66Cylinder #6 Injector : Current Above Normal
- 67Cylinder #6 Injector : Not Responding Properly
- 75Cylinder #7 Injector : Current Below Normal
- 76Cylinder #7 Injector : Current Above Normal
- 7742Secondary Throttle Position Sensor: Erratic, Intermittent, or Incorrect
- 7743Secondary Throttle Position Sensor: Voltage Above Normal
- 7744Secondary Throttle Position Sensor: Voltage Below Normal
- 7748Secondary Throttle Position Sensor: Abnormal Frequency, Pulse Width, or Period
- 79912Need Service Tool Update
- 85Cylinder #8 Injector : Current Below Normal
- 86Cylinder #8 Injector : Current Above Normal
- 912Incorrect Throttle Switch Inputs
- 913Throttle Position Sensor : Voltage Above Normal
- 914Throttle Position Sensor : Voltage Below Normal
- 918Throttle Position signal abnormal
- 943Fuel Pressure open/short to +batt
- 944Fuel Pressure short to ground
- 95Cylinder #9 Injector : Current Below Normal
- 96Cylinder #9 Injector : Current Above Normal
- E100Low Engine Oil Pressure Warning
- E17High Engine Coolant Temperature Warning
- E190Engine Overspeed Warning
- E265User Defined Shutdown
- E272Inlet Air Restriction Warning
- E360Low Engine Oil Pressure
- SPN110FMI15Engine Coolant Temperature : High - Least Severe (1)
- SPN190Engine Overspeed
- SPN190FMI15Engine Overspeed
- SPN3563FMI3Engine Intake Manifold #1 Absolute Pressure : Voltage Above Normal
- SPN630FMI2Calibration Memory : Erratic, Intermittent or Incorrect
Safety-critical: confirm before use
Torque, lifting, and load-chart values are safety-critical. Never operate from these figures alone. Confirm against the official manual and a qualified technician.