Komatsu Track Dozer E11 Fault Code: KOMTRAX System Does Not Operate Normally
Also called Contents Of Display By Machine Monitor Are Different From Applicable Machine, HST Charge Pressure Monitor Lights Up In Red While Engine Is Running
KOMTRAX System Does Not Operate Normally · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
E11 on a Komatsu track dozer covers three distinct issues that share this code: the KOMTRAX telematics system not operating normally, the HST charge pressure monitor lighting up red while the engine is running, and the machine monitor displaying content that does not match the machine it is installed on. There is no single fix. Diagnosis depends on which of the three conditions is actually present on the machine.
Medium severity. None of the three E11 conditions are described by Komatsu as causing immediate machine shutdown or damage. KOMTRAX communication loss and mismatched monitor display are informational problems that do not affect machine operation. The HST charge pressure red light is a warning tied to brake pressure and should be checked promptly, but no critical action level or controller shutdown is listed.
What does Komatsu Track Dozer error code E11 mean?
This code number actually groups three unrelated problems that Komatsu documents together. The first is a KOMTRAX system malfunction: KOMTRAX is Komatsu's remote machine-monitoring and telematics system, and when it stops operating normally, Komatsu notes that the trouble does not necessarily show up as anything the operator can see on the machine itself. It is usually the KOMTRAX system administrator, not the operator, who flags this for troubleshooting.
The second condition is the HST charge pressure monitor lighting up red while the engine is running. HST stands for hydrostatic transmission, and the charge pressure system keeps that transmission's hydraulic circuit supplied with pressurized oil. Komatsu ties this specific warning light to brake pressure: the related brake pressure sensor and brake pressure values can be checked through the monitor's own diagnostic codes.
The third condition is simpler: the machine monitor is showing display content that does not match the machine it is installed in, for example wrong menus, units, or machine-specific screens. Komatsu attributes this directly to a defective machine monitor.
Common causes of E11
- For KOMTRAX system not operating normally: defective power supply to the KOMTRAX terminal
- For KOMTRAX system not operating normally: defective starting switch ACC signal or defective alternator R signal
- For KOMTRAX system not operating normally: defective starting switch C signal
- For KOMTRAX system not operating normally: defective communication environment (poor signal or coverage)
- For KOMTRAX system not operating normally: defective GPS measurement
- For HST charge pressure monitor lighting up red: a genuine decrease in brake pressure, meaning the system is actually working properly and warning as designed
- For HST charge pressure monitor lighting up red: a defective brake pressure system
- For machine monitor showing wrong content: a defective machine monitor unit
How to troubleshoot Komatsu Track Dozer E11: first checks
- Identify which of the three E11 conditions applies to your machine: check whether the complaint is a KOMTRAX communication problem, a red HST charge pressure light on the monitor, or wrong display content on the monitor screen. The troubleshooting path is completely different for each.
- If it is a KOMTRAX issue, this is often only flagged remotely by the system administrator since it may not show any visible symptom on the machine. Check the starting switch ACC signal and alternator R signal wiring and connectors, check the starting switch C signal circuit, and inspect the KOMTRAX terminal's power supply wiring for looseness or corrosion.
- If it is the HST charge pressure monitor lighting red, use the machine monitor's built-in diagnostic functions to check brake pressure sensor signal voltage (monitoring code 91903) and actual brake pressure (monitoring code 91902) before assuming a sensor or system fault. A genuine low brake pressure reading may mean the warning system is doing exactly what it should.
- If it is a mismatched or wrong display on the machine monitor, this points to a defective machine monitor itself. Confirm the monitor's machine setting or configuration matches the actual machine model before replacing hardware.
- Check the KOMTRAX terminal's antenna and GPS reception if communication or location problems are suspected, since defective GPS measurement is a listed cause.
How the code clears
No reset procedure is listed for this code. Because E11 actually represents three separate conditions, clearing depends entirely on fixing the underlying cause identified above: correcting KOMTRAX wiring or communication issues, confirming or repairing the brake pressure system behind the HST charge pressure light, or replacing a defective machine monitor.
Frequently asked questions
What does Komatsu fault code E11 mean?
E11 is used by Komatsu for three different situations on track dozers: the KOMTRAX telematics system not working normally, the HST charge pressure monitor lighting up red while the engine runs, and the machine monitor showing display content that does not match the machine. Which one applies depends on what you are actually seeing on your machine.
Is E11 dangerous to keep operating with?
Komatsu does not list a controller shutdown action or critical action level for any of the three E11 conditions. A KOMTRAX fault or wrong monitor display does not affect how the machine drives or works. A red HST charge pressure light tied to low brake pressure deserves prompt attention since it can reflect a real drop in brake pressure.
Why does my HST charge pressure monitor light stay red while running?
Komatsu lists two causes: either brake pressure has actually decreased and the system is correctly warning you, or there is a defective brake pressure system. Check brake pressure sensor voltage and actual brake pressure through the monitor's diagnostic codes 91903 and 91902 before replacing parts.
Can a KOMTRAX problem affect how my dozer runs?
No. Komatsu specifically notes that even when the KOMTRAX system has trouble, that trouble does not particularly appear on the machine itself. It mainly affects remote monitoring and reporting, not machine operation.
What causes the KOMTRAX system to stop working normally?
Komatsu lists five possible causes: a defective power supply, a defective starting switch ACC signal or alternator R signal, a defective starting switch C signal, a defective communication environment, and defective GPS measurement.
My monitor is showing the wrong information for my machine. What's wrong?
Komatsu attributes this directly to a defective machine monitor. There is no other listed cause, so the monitor itself likely needs to be checked or replaced.
Do the quick and slow blinking KOMTRAX lamp patterns matter for diagnosing E11?
Yes. Komatsu defines quick blinking as periods of about 1 second (on and off every 0.5 seconds) and slow blinking as periods of about 4 seconds (on and off every 2 seconds). Check the KOMTRAX terminal lamp display pattern against Komatsu's testing and adjusting documentation to narrow down the specific fault.