Komatsu Track Dozer E15 Fault Code: Gearshift Mode Does Not Change
Also called Engine Coolant Temperature Gauge Does Not Indicate Correct Temperature
Gearshift Mode Does Not Change · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
E15 on a Komatsu track dozer covers two separate monitor problems: the engine coolant temperature gauge not showing the correct reading, or the gearshift mode display not changing when the switch is operated. Neither has a listed controller action or action level, so this code is mainly informational but should not be ignored since coolant temperature readings affect engine protection decisions.
Medium severity. E15 itself carries no listed action level or controller response, but a coolant temperature gauge that reads wrong can hide a real overheating problem, so treat the coolant-side version as worth prompt attention. The gearshift display version is a display/control annoyance rather than an immediate safety risk.
What does Komatsu Track Dozer error code E15 mean?
E15 is used for two different monitor complaints on Komatsu track dozers. The first is about the engine coolant temperature gauge: it may fail to rise out of the white (cold) range even though coolant temperature is actually rising normally, it may climb into the red (hot) range even though temperature is actually stable, or the gauge reading may simply not match the actual coolant temperature or the engine coolant temperature monitor reading.
The second version of E15 is about the gearshift mode switch: when the operator moves the gearshift mode switch, the speed mode section on the display does not change, even though the switch itself may be working fine.
Both versions point to a mismatch between what a sensor or switch is actually doing and what the machine monitor is showing the operator. The engine controller reads the coolant temperature sensor voltage and sends that data to the machine monitor over the CAN communication network, so a break anywhere in that sensor, wiring, or communication path can cause a bad gauge reading without any real coolant problem existing.
Common causes of E15
- Defective engine coolant temperature sensor system (sensor or its wiring/circuit)
- Defective machine monitor (display unit itself reading or showing values incorrectly)
- Defective power train controller (for the gearshift mode display symptom)
How to troubleshoot Komatsu Track Dozer E15: first checks
- Confirm actual coolant temperature using the monitoring function, code 04107 'Coolant Temperature,' and compare it against what the gauge is showing and against the physical condition of the engine.
- Before troubleshooting the gearshift mode display problem, check whether any related failure codes are also displayed. If DAFRMC, DK40KA, DK40KB, DLT3KA, or DLT3KB are present, troubleshoot those codes first since they can be the root cause.
- Inspect the coolant temperature sensor wiring and connectors for corrosion, looseness, or damage, since the sensor signal has to travel through the engine controller and CAN network before it reaches the monitor.
- Operate the gearshift mode switch several times while watching the speed mode section on the display to confirm the fault is repeatable and not an intermittent connection issue.
- Check the machine monitor itself for other display abnormalities, since a single defective monitor can produce both coolant gauge errors and gearshift display errors.
How the code clears
No reset procedure or clearing step is listed for this code. Diagnosis focuses on isolating whether the coolant temperature sensor system, the machine monitor, or (for the gearshift symptom) the power train controller is at fault, and repairing or replacing the faulty component.
Frequently asked questions
What does Komatsu E15 mean on a track dozer?
It means the machine monitor is showing either a coolant temperature reading that does not match actual conditions, or a gearshift mode display that does not update when the switch is used. It is not a single specific failure, it is a mismatch between a sensor/switch and what the display shows.
Is E15 dangerous to keep operating with?
There is no listed action level or controller response for E15, but if the coolant gauge is reading wrong, you lose a reliable way to catch real overheating. Use the monitoring function's coolant temperature reading (code 04107) to verify actual engine temperature rather than trusting the gauge alone.
How do I check the real coolant temperature if the gauge is acting up?
Use the machine monitor's built-in monitoring function, code 04107 labeled 'Coolant Temperature,' to see the actual sensor reading independent of the gauge display.
Why does my gearshift mode display not change when I press the switch?
Possible causes are a defective machine monitor or a defective power train controller. Before troubleshooting further, check for related failure codes DAFRMC, DK40KA, DK40KB, DLT3KA, or DLT3KB, since Komatsu says those should be diagnosed first if present.
Can a bad machine monitor cause both the coolant gauge and gearshift display problems?
Yes. A defective machine monitor is listed as a possible cause for both the coolant temperature gauge symptom and the gearshift mode display symptom, so a single monitor fault could explain both issues appearing together.
Does E15 have a specific reset or clearing procedure?
No reset procedure is listed for this code. Repair involves finding and fixing the faulty sensor, wiring, monitor, or controller, after which the display should return to normal.
Should I keep running the dozer if the coolant gauge is stuck in the white or jumps to red?
Since there's no listed action level, use the 04107 coolant temperature monitor reading to verify real engine temperature before deciding. If actual readings are within normal range, the fault is likely in the sensor circuit or monitor rather than true overheating, but confirm before assuming the gauge is simply wrong.