The Caterpillar C15 engine continued to serve as a workhorse for the heavy-duty trucking industry from 2004 to 2006. These model years brought small refinements and improved tuning, all while maintaining the engine’s reputation for reliability and torque.
Whether you’re maintaining a classic long-haul fleet or supporting vocational applications, understanding the fault codes on these engines can help reduce downtime and improve diagnostic speed. With Diesel Repair, it’s easy to get the info you need.
Caterpillar C15 (2004–2006) Overview
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- Displacement: 15.2L
- Horsepower Range: 435–550 HP
- Torque: Up to 1,850 lb-ft
- Emissions System: ACERT (with twin turbo and early emissions control)
- Fuel System: Electronic Unit Injector (EUI)
- Applications: Freightliner Classic, Kenworth T800/W900, Peterbilt 379, and other Class 8 models
📍 Get FREE Fault Code Information for all makes and models in Diesel Repair → Diesel Repair
Fault Codes for Caterpillar C15 (2004–2006)
| Fault | PID | SPN | FMI | SID | Title |
| 100-01 | 100 | 1 | Low Oil Pressure Warning | ||
| 100-03 | 100 | 3 | Oil Pressure Voltage High | ||
| 100-04 | 100 | 4 | Oil Pressure Voltage Low | ||
| 100-11 | 100 | 11 | Very Low Oil Pressure | ||
| 102-00 | 102 | Excessive Boost Pressure | |||
| 102-03 | 102 | 3 | Boost Pressure Voltage High | ||
| 102-04 | 102 | 4 | Boost Pressure Voltage Low | ||
| 1-05 | 651 | 5 | Cylinder No. 1 Injector Current Low | ||
| 105-00 | 105 | High Intake Manifold Air Temperature Warning | |||
| 105-03 | 105 | 3 | Intake Manifold Air Temperature Voltage High | ||
| 105-04 | 105 | 4 | Intake Manifold Air Temperature Voltage Low | ||
| 105-11 | 105 | 11 | Very High Intake Manifold Air Temperature | ||
| 1-06 | 651 | 6 | Cylinder No. 1 Injector Current High | ||
| 108-03 | 108 | 3 | Barometric Pressure Voltage High | ||
| 108-04 | 108 | 4 | Barometric Pressure Voltage Low | ||
| 110-00 | 110 | High Coolant Temperature Warning | |||
| 110-03 | 110 | 3 | Coolant Temperature Voltage High | ||
| 110-04 | 110 | 4 | Coolant Temperature Voltage Low | ||
| 110-11 | 110 | 11 | Very High Coolant Temperature | ||
| 111-01 | 111 | 1 | Low Coolant Level Warning | ||
| 111-02 | 111 | 2 | Coolant Level Signal Invalid | ||
| 111-03 | 111 | 3 | Coolant Level Voltage High | ||
| 111-04 | 111 | 4 | Coolant Level Voltage Low | ||
| 111-11 | 111 | 11 | Very Low Coolant Level | ||
| 111-14 | Low Coolant Level Warning | ||||
| 121-05 | 1072 | 5 | Low / High Retarder Current Low | ||
| 121-06 | 1072 | 6 | Low / High Retarder Current High | ||
| 122-05 | 1073 | 5 | Med / High Retarder Current Low | ||
| 122-06 | 1073 | 6 | Med / High Retarder Current High | ||
| 168-02 | 168 | 2 | ECM Battery Power Intermittent | ||
| 168-03 | 168 | 3 | High ECU Battery Power | ||
| 168-04 | 168 | 4 | Low ECU Battery Power | ||
| 171-03 | 171 | 3 | Ambient Air Temperature Voltage High | ||
| 171-04 | 171 | 4 | Ambient Air Temperature Voltage Low | ||
| 171-11 | 171 | 11 | Ambient Air Temperature Data Lost | ||
| 174-00 | 174 | High Fuel Temperature Warning | |||
| 174-03 | 174 | 3 | Fuel Temperature Voltage High | ||
| 174-04 | 174 | 4 | Fuel Temperature Voltage Low | ||
| 190-00 | 190 | Engine Overspeed Warning | |||
| 190-08 | 190 | 8 | Primary Engine Speed Loss of Signal | ||
| 190-12 | 190 | 12 | Primary Engine Speed Loss of Signal | ||
| 191-07 | 191 | 7 | Transmission Not Responding | ||
| 2-05 | 652 | 5 | Cylinder No. 2 Injector Current Low | ||
| 2-06 | 652 | 6 | Cylinder No. 2 Injector Current High | ||
| 212-03 | 620 | 3 | 5-Volt Sensor Supply No. 1 Voltage High | ||
| 212-04 | 620 | 4 | 5-Volt Sensor Supply No. 1 Voltage Low | ||
| 22-11 | 637 | 11 | Primary to Secondary Engine Speed Signal Calibration | ||
| 22-13 | 637 | 13 | Engine Speed Signal Calibration Not Performed | ||
| 224-11 | 224 | 11 | Theft Deterrent Active | ||
| 224-14 | 224 | 14 | Theft Deterrent Active with Engine Cranking | ||
| 231-02 | 639 | 2 | J1939 Data Incorrect | ||
| 231-11 | 639 | 11 | J1939 Data Link Fault | ||
| 231-12 | 639 | 12 | J1939 Device Not Responding | ||
| 246-11 | 597 | 11 | Brake Pedal Switch No. 1 Fault | ||
| 247-11 | 603 | 11 | Brake Pedal Switch No. 2 Fault | ||
| 249-11 | 249 | 11 | J1922 Data Link Fault | ||
| 252-11 | 631 | 11 | Engine Software Incorrect | ||
| 253-02 | 630 | 2 | Check Customer or System Parameters | ||
| 253-11 | 630 | 11 | Check Transmission Customer Parameters | ||
| 283-05 | 2949 | 5 | Intake Valve Actuation System Oil Pressure Solenoid Current Low | ||
| 283-06 | 2949 | 6 | Intake Valve Actuation System Oil Pressure Solenoid Current High | ||
| 283-07 | 2949 | 7 | Intake Valve Actuation Oil Pressure Not Responding | ||
| 284-05 | 2988 | 5 | Engine Coolant Diverter Current Low | ||
| 284-06 | 2988 | 6 | Engine Coolant Diverter Current High | ||
| 285-05 | 2950 | 5 | Intake Valve Actuator No. 1 Current Low | ||
| 285-06 | 2950 | 6 | Intake Valve Actuator No. 1 Current High | ||
| 285-07 | 2950 | 7 | Intake Valve Actuator No. 1 Not Responding | ||
| 286-05 | 2951 | 5 | Intake Valve Actuator No. 2 Current Low | ||
| 286-06 | 2951 | 6 | Intake Valve Actuator No. 2 Current High | ||
| 286-07 | 2951 | 7 | Intake Valve Actuator No. 2 Not Responding | ||
| 287-05 | 2952 | 5 | Intake Valve Actuator No. 3 Current Low | ||
| 287-06 | 2952 | 6 | Intake Valve Actuator No. 3 Current High | ||
| 287-07 | 2952 | 7 | Intake Valve Actuator No. 3 Not Responding | ||
| 288-05 | 2953 | 5 | Intake Valve Actuator No. 4 Current Low | ||
| 288-06 | 2953 | 6 | Intake Valve Actuator No. 4 Current High | ||
| 288-07 | 2953 | 7 | Intake Valve Actuator No. 4 Not Responding | ||
| 289-05 | 2954 | 5 | Intake Valve Actuator No. 5 Current Low | ||
| 289-06 | 2954 | 6 | Intake Valve Actuator No. 5 Current High | ||
| 289-07 | 2954 | 7 | Intake Valve Actuator No. 5 Not Responding | ||
| 290-05 | 2955 | 5 | Intake Valve Actuator No. 6 Current Low | ||
| 290-06 | 2955 | 6 | Intake Valve Actuator No. 6 Current High | ||
| 290-07 | 2955 | 7 | Intake Valve Actuator No. 6 Not Responding | ||
| 30-08 | 644 | 8 | PTO Throttle Signal Invalid | ||
| 30-13 | 644 | 13 | PTO Throttle Out of Calibration | ||
| 3-05 | 653 | 5 | Cylinder No. 3 Injector Current Low | ||
| 3-06 | 653 | 6 | Cylinder No. 3 Injector Current High | ||
| 385-03 | 2948 | 3 | Intake Valve Actuation System Oil Pressure Voltage High | ||
| 385-04 | 2948 | 4 | Intake Valve Actuation System Oil Pressure Voltage Low | ||
| 4-05 | 654 | 5 | Cylinder No. 4 Injector Current Low | ||
| 4-06 | 654 | 6 | Cylinder No. 4 Injector Current High | ||
| 41-03 | 678 | 3 | 8-Volt Supply Voltage High | ||
| 41-04 | 678 | 4 | 8-Volt Supply Voltage Low | ||
| 43-02 | 158 | 2 | Key Switch Fault | ||
| 5-05 | 655 | 5 | Cylinder No. 5 Injector Current Low | ||
| 5-06 | 655 | 6 | Cylinder No. 5 Injector Current High | ||
| 52-11 | 52 | 11 | Air Inlet Shutoff Shutdown | ||
| 54-05 | 706 | 5 | Auxiliary Output No. 6 Current Low | ||
| 54-06 | 706 | 6 | Auxiliary Output No. 06 Current High | ||
| 55-05 | 707 | 5 | Auxiliary Output No. 07 Current Low | ||
| 55-06 | 707 | 6 | Auxiliary Output No. 07 Current High | ||
| 6-05 | 656 | 5 | Cylinder No. 6 Injector Current Low | ||
| 6-06 | 656 | 6 | Cylinder No. 6 Injector Current High | ||
| 64-08 | 723 | 8 | Secondary Engine Speed Loss of Signal | ||
| 64-12 | 723 | 12 | Secondary Engine Speed Loss of Signal | ||
| 71-00 | 592 | Idle Shutdown Override | |||
| 71-01 | 593 | 1 | Idle Shutdown | ||
| 71-07 | Engine Shutdown Occurrence | ||||
| 71-14 | 593 | 14 | PTO Shutdown | ||
| 84-00 | 84 | Vehicle Overspeed Warning | |||
| 84-01 | 84 | 1 | Vehicle Speed Loss of Signal | ||
| 84-02 | 84 | 2 | Vehicle Speed Signal Invalid | ||
| 84-08 | 84 | 8 | Vehicle Speed Signal Out of Range | ||
| 84-10 | 84 | 10 | Vehicle Speed Signal Rate of Change | ||
| 84-14 | 84 | 14 | Quick Stop Occurrence | ||
| 91-08 | 91 | 8 | Throttle Position Invalid | ||
| 91-13 | 91 | 13 | Throttle Sensor Calibration | ||
| Flash Code 55 | No Diagnostic Code Detected |
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