Caterpillar Inc. is a well-known company that makes construction and mining tools, diesel and natural gas engines, industrial gas turbines, and diesel-electric locomotives. Caterpillar equipment has onboard diagnostic tools that can make fault codes to show when something is wrong or not working right.
Please keep in mind that the fault codes used by Caterpillar can be different based on the model and type of equipment. Each fault number is linked to a specific problem or system error, which makes it easier for technicians to figure out what’s wrong and fix it.
Even though I don’t have access to a full and up-to-date list of Caterpillar fault codes, I can give you some examples of the kinds of fault codes you might find in Caterpillar equipment:
List of Caterpillar fault codes
| PID/SID | FMI | Fault | Description |
| 1 | 11 | injector solenoid cyl#1 | current below normal or open |
| 2 | 11 | injector solenoid cyl#2 | current below normal or open |
| 3 | 11 | injector solenoid cyl#3 | current below normal or open |
| 4 | 11 | injector solenoid cyl#4 | current below normal or open |
| 5 | 11 | injector solenoid cyl#5 | current below normal or open |
| 6 | 11 | injector solenoid cyl#6 | current below normal or open |
| 22 | 13 | ECU | speed signal calibration not performed |
| 30 | 8 | PTO | PTO throttle signal invalid |
| 30 | 13 | PTO | PTO throttle signal out of calibration flash codes |
| 32 | 5 | turbo wastegate solenoid | current below normal |
| 32 | 6 | turbo wastegate solenoid | current above normal or shorted to ground |
| 32 | 11 | turbo wastegate solenoid | current mismatch |
| 41 | 3 | 8 volt supply | voltage above normal or shorted high |
| 41 | 4 | 8 volt supply | voltage below normal or shorted low |
| 42 | 11 | Injection Actuation Pump | output failure |
| 43 | 2 | ECU | key switch |
| 64 | 2 | speed sensor | loss of signal |
| 64 | 11 | speed sensor | erratic data signal |
| 70 | 5 | intake heater | current beow normal |
| 70 | 6 | intake heater | current above normal or shorted to ground |
| 71 | 1 | idle | idle shutdown |
| 71 | 14 | PTO | PTO shutdown |
| 84 | 0 | vehicle speed sensor | over speed warning |
| 84 | 1 | vehicle speed sensor | loss of signal |
| 84 | 2 | vehicle speed sensor | erratic/incorrect data signal |
| 84 | 8 | vehicle speed sensor | signal out of normal range |
| 84 | 10 | vehicle speed sensor | abnornal rate of change |
| 84 | 14 | vehicle speed sensor | quick stop occurance |
| 91 | 8 | throttle position | invalid signal |
| 91 | 13 | throttle position | out of calibration |
| 94 | 1 | fuel pressure | low fuel pressure |
| 94 | 3 | fuel pressure | voltage above normal |
| 94 | 4 | fuel pressure | voltage below normal |
| 94 | 11 | fuel pressure | low cranking fuel pressure |
| 96 | 3 | fuel level | voltage above normal |
| 96 | 4 | fuel level | voltage below normal |
| 100 | 1 | oil pressure sensor | low pressure warning |
| 100 | 3 | oil pressure sensor | voltage above normal |
| 100 | 4 | oil pressure sensor | voltage below normal |
| 100 | 11 | oil pressure sensor | very low oil pressure |
| 102 | 1 | intake mfld pres sensor | low boost pressure |
| 102 | 3 | intake mfld pres sensor | voltage above normal or shorted high |
| 102 | 4 | intake mfld pres sensor | voltage below normal or open circuit |
| 102 | 2 | intake mfld pres sensor | data does not match current conditions |
| 102 | 7 | intake mfld pres sensor | not responding |
| 105 | 3 | intake mfld tem sensor | voltage above normal or shorted high |
| 105 | 4 | intake mfld tem sensor | voltage below normal or open circuit |
| 105 | 0 | intake mfld tem sensor | temperature above protection limit |
| 105 | 11 | intake mfld tem sensor | very high intake air temperature |
| 108 | 3 | barometric pres sensor | voltage above normal or shorted high |
| 108 | 4 | barometric pres sensor | voltage below normal or shorted low |
| 108 | 2 | barometric pres sensor | erratic/incorrect data signal |
| 110 | 3 | coolant temp sensor | voltage above normal or shorted high |
| 110 | 4 | coolant temp sensor | voltage below normal or open circuit |
| 110 | 0 | coolant temp sensor | temperature above normal range |
| 110 | 11 | coolant temp sensor | very high coolant temperature |
| 111 | 2 | coolant level sensor | invalid signal |
| 111 | 3 | coolant level sensor | voltage above normal or shorted high |
| 111 | 4 | coolant level sensor | voltage below normal or open circuit |
| 111 | 1 | coolant level sensor | level below normal range |
| 111 | 11 | coolant level sensor | very low coolant level |
| 128 | 3 | sec fuel level | voltage below normal or shorted low |
| 128 | 4 | sec fuel level | voltage above normal or shorted high |
| 164 | 2 | injection actuation pressure | erratic signal |
| 164 | 3 | injection actuation pressure | voltage above normal |
| 164 | 4 | injection actuation pressure | voltage below normal |
| 164 | 0 | injection actuation pressure | excessive pressure |
| 164 | 11 | injection actuation pressure | system failure |
| 168 | 2 | ECM failure | supply voltage intermittent |
| 168 | 1 | ECM failure | supply voltage low |
| 168 | 0 | ECM failure | supply voltage high |
| 173 | 0 | exhaust temperature | derate for high exhaust temperature |
| 173 | 11 | exhaust temperature | derate for very high exhaust temperature |
| 186 | 4 | PTO | PTO shutdown switch v oltage low |
| 186 | 14 | PTO | PTO shutdown switch occurance |
| 190 | 0 | engine speed | overspeed warning |
| 190 | 2 | engine speed | loss of data signal |
| 190 | 11 | engine speed | erratic signal |
| 224 | 11 | theft deterent | active signal |
| 224 | 14 | theft deterent | active signal when cranking |
| 231 | 2 | J1939 data | incorrect data fron J1939 |
| 231 | 11 | J1939 data | J1939 configuration |
| 231 | 12 | J1939 data | loss of data signal |
| 231 | 14 | J1939 data | transmission data link derate |
| 232 | 3 | 5 volt supply | voltage above normal |
| 232 | 4 | 5 volt supply | voltage below normal |
| 232 | 3 | sensor supply | voltage above normal or shorted high |
| 232 | 4 | sensor supply | voltage below normal or shorted low |
| 246 | 11 | brake pedal switch1 | switch not responding |
| 247 | 11 | brake pedal switch2 | switch not responding |
| 251 | 12 | injector power supply | low voltage for injector power supply |
| 251 | 2 | ECM failure | igniton power lost to ecm |
| 252 | 11 | ECU | incorrect engine software |
| 253 | 2 | ECU | customer or system parameters |
| 253 | 14 | ECU | OEM parameter not programmed |
| 311 | 14 | ATD | active regeneration inhibited due to low exhaust temperature |
| 314 | 3 | clean gas induction | CGI pressure sensor voltage above normal |
| 314 | 4 | clean gas induction | CGI pressure sensor voltage below normal |
| 315 | 2 | clean gas induction | CGI temp high |
| 315 | 3 | clean gas induction | CGI temp sensor voltage above normal |
| 315 | 4 | clean gas induction | CGI temp sensor voltage below normal |
| 316 | 0 | clean gas induction | CGI flow rate high |
| 316 | 3 | clean gas induction | CGI temp sensor voltage above normal |
| 316 | 4 | clean gas induction | CGI temp sensor voltage below normal |
| 316 | 11 | clean gas induction | CGI flow rate high |
| 316 | 14 | clean gas induction | CGI flow rate low |
| 317 | 5 | clean gas induction | CGI actuator shaft current below normal |
| 317 | 6 | clean gas induction | CGI actuator shaft current above normal |
| 324 | 0 | ATD | ATD differential pressure above limits |
| 320 | 0 | ATD | ATD filter temperature high |
| 320 | 1 | ATD | ATD filter temperature high |
| 320 | 11 | ATD | ATD filter temperature very high |
| 320 | 3 | ATD | ATD filter temperature sensor voltage above normal |
| 320 | 4 | ATD | ATD filter temperature sensor voltage below normal |
| 324 | 11 | ATD | ATD differntial pressure, high filter restriction |
| 324 | 3 | ATD | ATD differential pressure voltage above normal |
| 324 | 4 | ATD | ATD differential pressure voltage below normal |
| 324 | 2 | ATD | ATD differential pressure signal erratic |
| 324 | 1 | ATD | ATD differential pressure , filter restricted |
| 324 | 0 | ATD | ATD differential pressure above limits |
| 327 | 2 | ATD | ATD exhaust gas temperature 2 data drifted high |
| 327 | 3 | ATD | ATD exhaust gas temperature 2 voltage above normal |
| 327 | 4 | ATD | ATD exhaust gas temperature 2 voltage below normal |
| 332 | 3 | aftertreatment fuel pressure control | aftertreatment fuel pressure sensor voltage above normal |
| 332 | 4 | aftertreatment fuel pressure control | aftertreatment fuel pressure sensor voltage below normal |
| 332 | 11 | aftertreatment fuel pressure control | aftertreatment fuel presuure high |
| 333 | 5 | aftertreatment fuel pressure control | ARD solenoid current abovenormal |
| 333 | 6 | aftertreatment fuel pressure control | ARD solenoid current above normal |
| 334 | 5 | aftertreatment fuel actuator | ARD solenoid current below normal |
| 334 | 6 | aftertreatment fuel actuator | ARD solenoid current above normal |
| 335 | 5 | aftertreatment ignition | ARD ignition current below normal |
| 335 | 6 | aftertreatment ignition | ARD ignition current above normal |
| 336 | 3 | aftertreatment 2 fuel pressure | sensor voltage above normal |
| 336 | 4 | aftertreatment 2 fuel pressure | sensor voltage below normal |
| 336 | 11 | aftertreatment 2 fuel pressure | fuel pressure high |
| 341 | 5 | aftertreatment purge air actuator | ARD purge air current below normal |
| 341 | 6 | aftertreatment purge air actuator | ARD purge air current above normal |
| 349 | 1 | aftertreatment purge air actuator | ARD purge air pressure low |
| 349 | 7 | aftertreatment purge air actuator | ARD purge pressure not responding |
| 350 | 5 | aftertreatment air pressure control | ARD solenoid current below normal |
| 350 | 6 | aftertreatment air pressure control | ARD solenoid current above normal |
| 350 | 7 | aftertreatment air pressure control | ARD solenoid not responding |
| 356 | 11 | ATD | ARD failed to ignite |
| 357 | 11 | ATD | ARD loss of ignition |
| 360 | 11 | aftertreatment | parked regen manually disabled |
| 373 | 3 | ATD secondary differntial pressure | sensor voltage above normal |
| 373 | 4 | ATD secondary differntial pressure | sensor voltage below normal |