What is Komatsu PC210LC-10 Fault Code DA22KK?

Fault Code DA22KK on the Komatsu PC210LC-10 excavator indicates a malfunction in the engine control system's communication circuit, specifically related to CAN (Controller Area Network) communication errors between the engine ECM (Engine Control Module) and the monitor controller. This code triggers when the ECM detects inconsistent or interrupted data transmission on the CAN bus network, which is the digital highway allowing different control modules to communicate critical operational data.

The CAN communication system is essential for the PC210LC-10's integrated performance, as it coordinates engine parameters, hydraulic functions, and operator display information. When this code activates, the machine's ability to properly regulate engine speed, monitor temperatures, and display accurate diagnostic information becomes compromised. For used excavators, this fault is particularly concerning as degraded wiring harnesses and corroded connectors are common culprits after thousands of operating hours.

Common Symptoms

• Warning lamp illumination on the monitor panel, often accompanied by reduced engine power or limp mode activation
• Intermittent or blank display screens showing inaccurate readings for fuel level, engine temperature, or operating hours
• Engine RPM fluctuations or unexpected power derate, especially during high-demand operations
• Multiple fault codes appearing simultaneously due to communication breakdown between control modules
• Erratic hydraulic response as the system cannot properly coordinate engine load with hydraulic demand

Potential Causes

The DA22KK code typically stems from electrical circuit failures rather than mechanical issues. In used PC210LC-10 excavators, the most common causes include:

• Damaged or corroded CAN bus wiring harness, particularly at flex points near the engine compartment or cab where vibration and movement cause wire chafing
• Loose or oxidized connector terminals on the ECM or monitor controller, especially the 48-pin ECM connector known for moisture intrusion
• Failed terminating resistor on the CAN network (typically 120-ohm resistors at network endpoints)
• ECM internal fault or monitor controller failure, though less common than wiring issues
• Voltage irregularities from weak batteries or failing alternator causing network instability
• Aftermarket component interference if non-OEM accessories were improperly integrated into the electrical system

How to Troubleshoot and Fix Code DA22KK

Step 1: Visual Inspection of Wiring and Connectors Begin by thoroughly inspecting the CAN bus harness from the ECM (located on the right side of the engine) to the monitor controller in the cab. Look for abraded insulation, particularly where harnesses pass through grommets or contact metal edges. On used machines, check for oil contamination or UV damage to wire insulation. Disconnect and inspect the ECM connector and monitor connector, cleaning terminals with electrical contact cleaner and checking for bent pins or green corrosion.

Step 2: Electrical Testing with Diagnostic Tools Using a digital multimeter, verify proper CAN bus voltage (typically 2.5V nominal with fluctuations between 1.5-3.5V during communication). With the key on and engine off, backprobe the CAN-H and CAN-L wires at the ECM connector. Check for proper terminating resistance by measuring between CAN-H and CAN-L with all modules disconnected—you should read approximately 60 ohms (two 120-ohm resistors in parallel). Use Komatsu KOMTRAX or diagnostic software to monitor live CAN data and identify which module is failing to communicate.

Step 3: Component Replacement and Verification If wiring and voltage tests pass, suspect a failed monitor controller or ECM. Before replacing expensive components on used excavators, perform a power reset by disconnecting both batteries for 15 minutes to clear temporary glitches. Replace damaged harness sections using proper CAN-rated twisted pair cable with correct gauge (typically 20 AWG). After repairs, clear codes using diagnostic software and perform a complete operational test under load to ensure proper communication restoration.

---

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 diagnostic assistance for complex electrical issues. Improper repairs to CAN systems can cause additional control module damage.