What is Komatsu PC210LC-10 Fault Code E-36?

Fault Code E-36 on the Komatsu PC210LC-10 indicates an Engine Controller (ECM) communication error with the main machine controller or a malfunction in the engine control system's internal circuitry. This code typically signals a breakdown in the Controller Area Network (CAN) bus communication between the engine ECM and the machine's primary monitor panel.

This fault is critical because the ECM serves as the brain of the PC210LC-10's emission-compliant SAA6D107E-1 engine. When communication fails, the machine cannot properly regulate fuel injection timing, turbocharger boost pressure, or exhaust gas recirculation (EGR) functions. For operators of used excavators, this code often appears after years of electrical harness degradation or moisture infiltration in connector terminals, making it a common age-related issue rather than a catastrophic failure.

Common Symptoms

• Warning light illumination on the monitor panel, often accompanied by a "Check Engine" or communication error icon
• Loss of engine power or inability to exceed mid-range RPMs (approximately 1,400-1,600 RPM limit)
• Erratic instrument cluster readings, including fuel gauge fluctuations or tachometer dropouts
• Failure of automatic functions such as auto-idle or auto-shutdown timers
• Intermittent starting issues where the engine cranks but struggles to fire, then runs normally after warming

Potential Causes

The most common technical reasons for E-36 on used PC210LC-10 excavators include:

• CAN bus wiring harness damage at known friction points near the engine firewall or along the right-side engine bay where harnesses contact frame members
• Corroded or moisture-contaminated connectors at the ECM (located under the cab floor) or at the monitor panel connector behind the operator seat
• Failed ECM internal circuitry, particularly in machines with 8,000+ operating hours where capacitor degradation occurs
• Low battery voltage (below 22V on dual 12V systems) causing communication dropouts during cranking
• Aftermarket component interference, especially non-OEM alarm systems or tracking devices wired into the CAN network

How to Troubleshoot and Fix Code E-36

Step 1: Verify Power Supply and Battery Condition Using a digital multimeter, check battery voltage at rest (should read 24-26V) and during cranking (shouldn't drop below 22V). Inspect battery cable terminals and the main ground strap connection at the engine block for corrosion—a common issue on used machines stored outdoors.

Step 2: Inspect CAN Bus Harness and Connectors Physically trace the CAN-H and CAN-L wires (typically orange and green in Komatsu harnesses) from the ECM to the monitor panel. Check for harness chafing at the firewall grommet and where cables pass near the hydraulic tank. Disconnect the main ECM connector (22-pin gray connector) and inspect for green corrosion or bent pins—spray with contact cleaner and apply dielectric grease before reconnecting.

Step 3: Perform Diagnostic Software Analysis Connect Komatsu KOMTRAX or compatible diagnostic software (such as Nexiq with appropriate licenses) to the diagnostic port under the cab. Monitor live CAN bus data to identify whether the ECM is transmitting signals. Check for resistance between CAN-H and CAN-L wires at the ECM connector (should read 55-65 ohms). On used excavators, failed terminating resistors within the ECM or monitor are common after thermal cycling over years.

Step 4: Clear Code and Test After repairs, clear the fault code using diagnostic software and run the machine through a full operating cycle. If E-36 returns immediately, ECM replacement is likely necessary—always source genuine Komatsu ECMs with matching part numbers, as software versions are critical for the PC210LC-10's tier-compliant engine.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu service manual for your specific machine serial number and consider professional diagnostics for complex electrical issues, especially when dealing with emissions-controlled systems.