What is Komatsu PC210-10 Fault Code DAZQKR?

Fault Code DAZQKR on the Komatsu PC210-10 indicates a communication error between the engine ECM (Engine Control Module) and the machine monitor or display system. This diagnostic trouble code specifically points to an interruption or failure in the CAN bus communication network that connects critical control systems.

The CAN (Controller Area Network) bus is the digital backbone of modern Komatsu excavators, allowing the engine controller, hydraulic systems, and operator display to exchange real-time data. When this communication pathway fails, the machine loses its ability to properly monitor engine parameters, report system status, or implement protective functions. For the PC210-10 model equipped with advanced Komtrax telematics and integrated machine control, this fault can severely impact operational efficiency and prevent accurate diagnostics of other potential issues.

Common Symptoms

When Code DAZQKR is active on your PC210-10, you may experience:

• Warning lamp illumination on the machine monitor with reduced or frozen display information
• Loss of real-time data including engine temperature, fuel level, or hydraulic oil temperature readings on the monitor
• Intermittent gauge operation where the display flickers or shows incorrect values
• Engine derate mode may activate as a precautionary measure if critical sensor data cannot be verified
• Komtrax system failure to transmit machine data or operating hours to remote monitoring platforms

Potential Causes

The most common technical causes for DAZQKR on used PC210-10 excavators include:

• CAN bus wiring harness damage – particularly at flex points near the cab mounting or boom connections where repeated movement causes wire insulation breakdown
• Corroded or loose connector pins on the main harness connector between the engine compartment and cab (C101 connector notorious for moisture intrusion)
• Failed monitor display unit with internal communication board failure
• ECM power supply issues including poor ground connections at the engine block mounting point
• Termination resistor failure at either end of the CAN bus network (typically 120-ohm resistors)
• EMI (Electromagnetic Interference) from aftermarket radios or accessories improperly installed on the CAN network

How to Troubleshoot and Fix Code DAZQKR

Step 1: Visual Harness Inspection Begin with a thorough physical inspection of the main wiring harness routing from the engine ECM (located right side of engine) to the cab. On used excavators, focus on areas where the harness passes through the rotating house frame and near hydraulic lines. Look for abraded insulation, pinched wires, or signs of heat damage. Pay special attention to the C101 connector behind the cab – disconnect, inspect for green corrosion, and clean with electrical contact cleaner.

Step 2: CAN Bus Voltage Testing Using a digital multimeter, backprobe the CAN-High and CAN-Low wires at the ECM connector (typically pins 23 and 24 on the PC210-10). With ignition on, engine off, you should measure approximately 2.5V on each line with 0V difference between them at rest. During communication, voltage should fluctuate between 1.5-3.5V. If readings are flat or outside this range, the communication network is compromised.

Step 3: Termination Resistance Check With the ignition off and battery disconnected, measure resistance between CAN-High and CAN-Low terminals. You should read approximately 60 ohms (two 120-ohm resistors in parallel). A reading of 120 ohms indicates one termination resistor has failed; infinite resistance means both are faulty or the circuit is open.

Step 4: ECM and Monitor Ground Verification Check the ECM ground strap at the engine block and the monitor ground behind the cab panel. These ground points are critical for proper CAN communication. Clean all contact surfaces to bare metal and verify less than 0.5 ohms resistance to battery negative.

Step 5: Software Diagnostics Connect Komatsu KOMPC diagnostic software or an approved J1939 diagnostic tool to retrieve detailed fault data. Check for additional stored codes that may indicate whether the ECM or monitor is the source of the communication failure. The software can also perform a CAN bus health check to identify weak nodes.

For used excavators, replacing the entire main harness may be necessary if multiple repair attempts fail, as internal wire damage from years of vibration cannot always be detected externally.

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Professional Disclaimer: This guide provides general troubleshooting information for experienced heavy equipment technicians. Always consult the official Komatsu PC210-10 Shop Manual and follow proper lockout/tagout procedures. If you lack the specialized diagnostic tools or experience with CAN bus systems, contact an authorized Komatsu dealer or certified diesel mechanic to prevent further damage to electronic components.