Komatsu PC210LC-8M0 Fault Code DAZQKR: Complete Diagnostic Guide

What is Komatsu PC210LC-8M0 Fault Code DAZQKR?

Fault Code DAZQKR indicates a communication error between the engine ECM (Engine Control Module) and the machine controller on the Komatsu PC210LC-8M0 excavator. This diagnostic trouble code signals that the CANbus data link has experienced an interruption or abnormal signal transmission between critical control systems.

This code specifically affects the SAE J1939 communication protocol that allows the engine controller and machine systems to exchange vital operational data. The PC210LC-8M0 relies on this real-time data exchange to coordinate engine output, hydraulic demands, and emission controls. When communication fails, the machine may enter a protective derate mode to prevent potential damage from uncoordinated system operation.

Common Symptoms

When DAZQKR is active, operators typically experience:

• Warning lamp illumination on the instrument cluster, often accompanied by reduced engine power
• Engine derate limiting maximum RPM to 1500-1800 range, severely restricting digging force
• Erratic gauge readings including incorrect fuel level, water temperature, or hour meter displays
• Intermittent loss of monitor functions where the multi-information display shows error messages or goes blank
• Hydraulic system irregularities as the coordinated control between engine load and pump demand fails

Potential Causes

The most common technical causes for DAZQKR on used PC210LC-8M0 excavators include:

• Corroded or damaged CANbus connectors at the ECM or machine controller harness connections (particularly the X201 connector behind the cab)
• Harness wire chafing where the main wire bundle passes through the firewall or along the right-hand track frame—a known wear point on this model
• Faulty termination resistors in the CAN network (120-ohm resistors that maintain signal integrity)
• ECM or machine controller internal failure, though less common than harness issues
• Voltage fluctuations from failing alternators or poor battery connections affecting controller stability
• Water intrusion in sealed connectors from deteriorated O-rings or damaged conduit boots

How to Troubleshoot and Fix Code DAZQKR

Step 1: Visual Inspection Begin by inspecting all CAN harness connectors for corrosion, bent pins, or moisture. On used excavators, focus on the ECM connector (located on the right side of engine compartment) and the machine controller connector near the operator's seat. Check for green corrosion buildup indicating water intrusion.

Step 2: Resistance Testing Using a digital multimeter, measure resistance between CAN-High and CAN-Low terminals with the key off and all connectors attached. You should read approximately 60 ohms (two 120-ohm terminators in parallel). A reading of 120 ohms suggests one missing terminator; infinite resistance indicates an open circuit in the harness.

Step 3: Voltage Verification With the key on and engine off, measure voltage at the CAN-High and CAN-Low lines. Both should show approximately 2.5 volts at rest. While monitoring with Komatsu KOMTRAX diagnostic software or compatible scan tool, wiggle harnesses to identify intermittent connection failures.

Step 4: Targeted Repairs For used machines, replace any corroded connectors completely rather than attempting to clean them. Inspect known rub points along the frame rail where zip ties may have failed. Apply dielectric grease to all reconnected terminals.

Disclaimer: This guide provides general diagnostic direction. Complex electrical issues or ECM replacement should be performed by Komatsu-certified technicians with proper diagnostic equipment to avoid costly misdiagnosis.