What is Komatsu PC210-10 Fault Code E-19?

Komatsu PC210-10 Fault Code E-19 indicates a malfunction in the engine coolant temperature sensor circuit or an abnormal engine temperature reading detected by the Engine Control Module (ECM). This code specifically signals that the ECM has received an out-of-range signal from the coolant temperature sensor, which monitors the engine's operating temperature to optimize fuel injection, combustion efficiency, and emission controls.

For the Komatsu PC210-10's SAA6D107E-1 engine, accurate coolant temperature monitoring is critical for maintaining proper engine performance and preventing catastrophic overheating. When the ECM cannot reliably read coolant temperature, it may trigger protective derate modes that limit engine power to prevent potential damage. This fault directly impacts hydraulic performance since the PC210-10's hydraulic system relies on consistent engine output for optimal digging force and cycle times.

Common Symptoms

When Fault Code E-19 is active on your Komatsu PC210-10, you may experience:

• Engine warning light illuminated on the instrument cluster, often accompanied by an audible alarm
• Reduced engine power or automatic derate mode, limiting maximum RPM to approximately 1,500-1,800 RPM
• Erratic temperature gauge readings, showing sudden spikes, drops, or fluctuating between extremes
• Hard starting or rough idle when the engine is cold, as the ECM receives incorrect temperature data for fuel mapping
• Black smoke from the exhaust due to improper fuel-air mixture caused by faulty temperature compensation

Potential Causes

The following technical issues commonly trigger E-19 on used PC210-10 excavators:

• Failed coolant temperature sensor (most common on machines with 5,000+ operating hours)
• Damaged or corroded wiring harness at the sensor connector, particularly where the harness routes near the engine block and experiences heat cycling
• Shorted or open circuit in the sensor wiring between the sensor and ECM connector (check harness routing points where friction against frame rails occurs)
• Corroded ECM connector pins at the C2 connector where coolant temperature signals terminate
• Failed ECM internal circuit (rare, but possible on heavily used machines exposed to moisture or electrical system issues)
• Low coolant level causing air pockets near the sensor, resulting in inaccurate readings

How to Troubleshoot and Fix Code E-19

Step 1: Visual Inspection Begin by inspecting the coolant temperature sensor located on the left side of the engine block near the thermostat housing. Check the sensor connector for corrosion, damaged pins, or coolant contamination. On used excavators, verify the wiring harness for visible damage, especially where it contacts hot engine surfaces or rubs against metal edges.

Step 2: Test Sensor Resistance Disconnect the sensor connector and use a digital multimeter to measure resistance across the sensor terminals. At room temperature (20°C/68°F), resistance should read approximately 2,300-2,700 ohms. At operating temperature (80°C/176°F), resistance should drop to approximately 300-350 ohms. Values significantly outside this range indicate sensor failure.

Step 3: Check Circuit Continuity With the sensor disconnected, test for continuity between the sensor harness connector and ECM connector C2 (pins typically designated for temperature signal and ground). Resistance should be less than 1 ohm. Also check for shorts to ground by measuring resistance between each wire and chassis ground (should read infinite/OL).

Step 4: Verify Supply Voltage With ignition on and sensor connected, backprobe the sensor connector to measure voltage. You should see approximately 5 volts on the signal wire. If voltage is absent or incorrect, trace the harness to the ECM and inspect for damaged wires or poor ECM connections.

Step 5: Clear Code and Monitor After repairs, use Komatsu KOMTRAX diagnostic software or a compatible scan tool to clear the fault code. Run the engine through temperature cycles while monitoring live data to confirm the sensor reads correctly and the code doesn't return.

For used excavators, always inspect connector seals and apply dielectric grease to prevent future corrosion issues common in aging machines.

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Disclaimer: This guide provides general troubleshooting information for Komatsu PC210-10 Fault Code E-19. Always consult the official Komatsu service manual for your specific machine serial number and seek professional assistance from certified Komatsu technicians for complex repairs or when safety concerns exist.