Caterpillar 3126B troubleshooting: 17 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Caterpillar 3126B — full specs, parts & maintenance.
| Code | Meaning | Remedy |
|---|---|---|
| i01462046 | Engine Stopping | Stop the engine according to the procedure in the Operation and Maintenance Manual, “Engine Stopping (Operation Section)” in order to avoid overheating of the engine and accelerated wear of the engine components. Use the Emergency Stop Button (if equipped) ONLY in an emergency situation. Do not use the Emergency Stop Button for normal engine stopping. After an emergency stop, DO NOT start the engine until the problem that caused the emergency stop has been corrected. |
| i01463504 | Fault Logging | The system provides the capability of Fault Logging. When the Electronic Control Module (ECM) generates an active diagnostic code, the code will be logged in the memory of the ECM. |
| i01324374 | Engine Operation with Active Diagnostic Codes | If the diagnostic lamp starts to flash codes during normal engine operation, the system has identified a situation that is not within the specification. Use Caterpillar electronic service tools to check the active diagnostic codes. |
| i01456915 | Engine Operation with Intermittent Diagnostic Codes | If the diagnostic lamp starts to flash codes during normal engine operation and the diagnostic lamp shuts off, an intermittent fault may have occurred. If a fault has occurred, the fault will be logged into the memory of the Electronic Control Module (ECM). |
| i01324368 | An intermittent failure in the TPS causes the engine speed to vary erratically. | |
| 1000; 1900; 1901; 1902 | The “DIAGNOSTIC” lamp flashes codes for any active diagnostic codes. | |
| Diagnostic Flash Code | The “DIAGNOSTIC” lamp flashes in order to indicate a two-digit code. |
| Symptom | Cause | Remedy |
|---|---|---|
| Overspeed condition during initial start-up or overhauled engine | Stop the engine by shutting off the fuel supply to the engine and/or shutting off the air supply to the engine. | |
| Loose or frayed electrical wires | Check the electrical wires daily for wires that are loose or frayed. Tighten all loose electrical wires before the engine is started. Repair all frayed electrical wires before the engine is started. See the Operation and Maintenance Manual for specific starting instructions. | |
| Improper grounding | Proper grounding for the engine electrical system is necessary for optimum engine performance and reliability. Improper grounding will result in uncontrolled electrical circuit paths and in unreliable electrical circuit paths. Uncontrolled electrical circuit paths can result in damage to main bearings, to crankshaft bearing journal surfaces, and to aluminum components. Engines that are installed without engine-to-frame ground straps can be damaged by electrical discharge. To ensure that the engine and the engine electrical systems function properly, an engine-to-frame ground strap with a direct path to the battery must be used. This path may be provided by way of a direct engine ground to the frame. All grounds should be tight and free of corrosion. The engine alternator must be grounded to the negative “-” battery terminal with a wire that is adequate to handle the full charging current of the alternator. | |
| Low Power | Check the adjustments for the Throttle Position Sensor. | |
| Reduced Engine Speed | Shut down the Engine(1); Service(2); Schedule Service for the Engine.(3) | |
| Excessive Smoke | The operator should log any observation that could have caused the lamp to light. This information can be useful to help troubleshoot the situation. | |
| Failure of the Boost Pressure Sensor will not cause a shutdown of the engine. | The ECM will detect failure of the boost pressure sensor. The operator will be warned of the problem through the diagnostic lamp. The strategies that are related to the boost will be disabled. Engine power will be severely reduced in the event of a failure of the boost pressure sensor. | |
| Failure of the Coolant Temperature Sensor will not cause a shutdown of the engine or any horsepower change. | The ECM will detect a failure of the coolant temperature sensor. The diagnostic lamp will warn the operator about the status of the coolant temperature sensor. | |
| Failure of the Engine Oil Pressure Sensor will not cause a shutdown of the engine or any horsepower change. | The ECM will detect failure of the engine oil pressure sensor. The diagnostic lamp warns the user about the status of the engine oil pressure sensor. The engine oil pressure related strategies will be disabled in the event of a failure of the engine oil pressure sensor. | |
| If the ECM does not receive a signal from primary speed/timing sensor (6), the “DIAGNOSTIC” lamp will indicate a diagnostic fault code which will be logged in the ECM memory. | The ECM will read the signal from the secondary speed/timing sensor. The ECM continually checks in order to determine if there is a signal from both sensors. If either sensor fails, the faulty sensor should be replaced. Intermittent failure of the sensors will cause erratic engine control. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: The ECM will detect failure of the boost pressure sensor. The operator will be warned of the problem through the diagnostic lamp. The strategies that are related to the boost will be disabled. Engine power will be severely reduced in the event of a failure of the boost pressure sensor.. See the table for the matching fixes.
Documented causes: The ECM will detect a failure of the coolant temperature sensor. The diagnostic lamp will warn the operator about the status of the coolant temperature sensor.. See the table for the matching fixes.
Documented causes: The ECM will detect failure of the engine oil pressure sensor. The diagnostic lamp warns the user about the status of the engine oil pressure sensor. The engine oil pressure related strategies will be disabled in the event of a failure of the engine oil pressure sensor.. See the table for the matching fixes.