Komatsu Track Dozer E10 Fault Code: Service Meter Does Not Operate While Engine is Running
Also called Engine Oil Pressure Monitor Lights Up In Red While Engine Is Running, Hydraulic Temperature Gauge (Multi-Gauge) Does Not Indicate Normally
Service Meter Does Not Operate While Engine is Running · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
E10 on a Komatsu track dozer covers three separate monitor complaints grouped under this code: the engine oil pressure warning lighting up red while running, the hydraulic oil temperature gauge on the multi-gauge not reading normally, and the service meter not counting hours while the engine runs. These are distinct problems that share the E10 designation, so diagnosis depends on which symptom is actually happening.
High severity. An engine oil pressure warning lighting up while running can mean a real loss of oil pressure, which risks engine damage if ignored. The hydraulic temperature gauge and service meter issues are lower risk on their own, mostly monitor or wiring faults, but any oil pressure warning should be treated as urgent until proven otherwise.
What does Komatsu Track Dozer error code E10 mean?
E10 is not one single failure. Komatsu groups three different monitor-related complaints under this code: the engine oil pressure monitor lighting up red while the engine runs, the hydraulic oil temperature gauge on the multi-gauge failing to indicate normally, and the service meter (the hour counter) not operating while the engine runs.
For the oil pressure warning, the controller itself does not monitor the ON/OFF signal from the engine oil pressure switch directly. Instead, if the engine oil pressure switch turns ON while the engine is running, a separate failure code is sent from the engine controller to the machine monitor over CAN, which then lights the red warning.
For the hydraulic temperature gauge issue, the gauge either fails to rise out of the white range as oil temperature rises normally, or it rises into the red range even though the oil temperature is actually stable. For the service meter issue, the hour meter fails to accumulate time while the engine is running, even though it should keep running any time the engine is on, moving or not, and should stop only when the engine is stopped.
Common causes of E10
- Engine oil pressure monitor lighting up: reduction of actual engine oil pressure (the system may be working correctly and warning you of a real condition)
- Engine oil pressure monitor lighting up: defective engine oil pressure system (switch or related wiring)
- Engine oil pressure monitor lighting up: defective machine monitor
- Hydraulic oil temperature gauge not indicating normally: defective machine monitor
- Service meter not operating while engine is running: defective service meter
- Service meter not operating while engine is running: disconnection in the wiring harness, including a broken wire or a poor contact in a connector
How to troubleshoot Komatsu Track Dozer E10: first checks
- If the engine oil pressure monitor lights up red while running, treat it as a possible real oil pressure loss first. Check engine oil level and condition before assuming it is a false alarm.
- Check the engine oil pressure switch and its wiring and connectors for damage, corrosion, or loose contacts if oil level and condition are normal.
- Use the machine monitor's monitoring function (Code 04401, Hydraulic Oil Temperature) to compare the actual hydraulic oil temperature reading against what the gauge is displaying, to isolate a gauge display problem from an actual temperature problem.
- For the service meter, verify whether it counts time only while the engine runs and stops when the engine is off. If it never counts, inspect the wiring harness for disconnection or poor connector contact before condemning the meter itself.
- Cross-check any related E-1 troubleshooting information if the service meter complaint is present, since Komatsu ties this symptom back to that procedure.
How the code clears
No separate reset or clearing procedure is listed for E10. Since this code covers three distinct symptoms (oil pressure monitor, hydraulic temperature gauge, and service meter), the fix depends entirely on which condition is found: repairing the oil pressure system, replacing the machine monitor, or repairing the wiring harness or connector for the service meter.
Frequently asked questions
What does Komatsu fault code E10 mean?
E10 groups three separate monitor complaints on Komatsu track dozers: the engine oil pressure warning lighting up red while the engine runs, the hydraulic oil temperature gauge not indicating normally, and the service meter failing to count hours while the engine runs.
Is E10 safe to keep operating with?
If the symptom is the engine oil pressure monitor lighting up, do not keep operating without checking oil level and pressure first, since this can indicate a real loss of engine oil pressure. The hydraulic temperature gauge and service meter symptoms are not immediately dangerous but should still be diagnosed.
Why does my hydraulic oil temperature gauge not move even though the oil is heating up?
Komatsu lists a defective machine monitor as the cause when the gauge fails to rise out of the white range during normal warm-up, or rises into the red range when the oil temperature is actually stable. Comparing the gauge to the monitor's Code 04401 hydraulic oil temperature reading can confirm this.
Why is my service meter not counting hours while the engine is running?
Komatsu lists a defective service meter or a disconnection in the wiring harness, including a broken wire or poor connector contact, as the possible causes. The meter should run continuously while the engine is on, whether the machine is moving or not, and stop only when the engine is off.
Does the controller monitor the engine oil pressure switch directly?
No. The controller does not monitor the ON/OFF signal from the engine oil pressure switch itself. Instead, the engine controller sends a failure code to the machine monitor over CAN when the switch turns ON while the engine is running, which triggers the red warning light.
What should I check first if the oil pressure warning light comes on?
Check engine oil level and condition first, since a real drop in oil pressure is one of Komatsu's listed causes. If oil level and condition are fine, inspect the oil pressure switch and its wiring for a defective system before suspecting the machine monitor.