What is Komatsu PC110-8M0 Fault Code AB00KE?

Fault Code AB00KE indicates a communication error or malfunction in the excavator's main controller network, specifically affecting the CAN (Controller Area Network) bus system between the engine ECM (Engine Control Module) and the hydraulic controller. This diagnostic trouble code is part of Komatsu's proprietary fault code system for their Dash-8M0 series excavators.

In the PC110-8M0 model, this code signals that the primary control modules cannot properly exchange critical operational data. The CAN bus serves as the central nervous system for modern excavators, enabling real-time communication between the engine management system, hydraulic controllers, and machine monitoring systems. When communication fails, the excavator cannot optimize fuel delivery, hydraulic flow, or implement safety protocols, potentially leading to reduced performance or complete shutdown to prevent damage.

Common Symptoms

When Code AB00KE is active, operators typically experience:

• Warning lights illuminated on the monitor panel, specifically the system malfunction indicator and check engine light simultaneously
• Engine derate mode where power output is limited to 60-70% of normal capacity to protect components
• Erratic hydraulic response including inconsistent swing speed, boom/arm movement delays, or fluctuating attachment operation
• Intermittent gauge readings with the monitor display showing unstable engine RPM, temperature, or pressure values
• Engine shutdown or failure to start in severe cases where the ECM cannot verify safe operating parameters

Potential Causes

The most common technical failures triggering AB00KE in used PC110-8M0 excavators include:

Wiring harness damage at known rub points—particularly where the main harness runs along the right side frame rail near the hydraulic pump, where vibration causes insulation wear and wire exposure.

Corrosion in controller connectors, especially the 38-pin ECM connector located behind the access panel on the right side of the engine compartment, which is vulnerable to moisture intrusion in machines operating in wet or coastal environments.

Failed terminating resistors on the CAN bus network (120-ohm resistors at network endpoints) causing signal reflection and data corruption.

ECM or hydraulic controller internal failure, more common in machines exceeding 8,000 operating hours where capacitor degradation affects signal processing.

Poor grounding connections at the battery terminal or frame ground points, creating voltage fluctuations that disrupt digital communication.

Aftermarket component interference, particularly non-OEM attachment controllers or monitoring systems improperly integrated into the CAN network.

How to Troubleshoot and Fix Code AB00KE

Step 1: Perform Initial Visual Inspection

Begin by examining all wiring harnesses running from the engine bay to the operator's cab. Focus on the main harness bundle along the right frame rail—check for abraded insulation, exposed copper, or evidence of previous repairs with electrical tape. Inspect all connector housings for corrosion, bent pins, or moisture. Remove the ECM connector and hydraulic controller connector, checking for green oxidation on pins (common in machines over 5 years old).

Step 2: Test CAN Bus Integrity

Using a digital multimeter set to resistance mode, disconnect both the ECM and hydraulic controller. Measure resistance between CAN-High and CAN-Low terminals at the ECM connector (typically pins 24 and 25 on Komatsu systems). You should read approximately 60 ohms with the system off, indicating both 120-ohm terminating resistors are present and functioning. A reading of 120 ohms means one resistor has failed; an open circuit (infinite resistance) indicates complete network failure or broken wiring.

Step 3: Check Ground Circuit Continuity

Verify the ground circuit from the ECM case to the battery negative terminal shows less than 0.5 ohms resistance. Clean all ground connection points with a wire brush and apply dielectric grease. For used excavators, corrosion at the frame ground bolt (located near the battery box) is a frequent culprit.

Step 4: Utilize Komatsu Diagnostic Software

Connect Komatsu KOMTRAX or PC-based diagnostic software to the service port beneath the operator's seat. Monitor live CAN bus traffic to identify which controller is failing to transmit. The software will show message error rates—anything above 5% indicates a failing module or wiring issue between specific components.

Step 5: Replace or Repair Identified Components

If harness damage is found at rub points, do not simply wrap with tape—cut out the damaged section and splice with solder and heat-shrink tubing rated for automotive use, or replace the entire harness section. When replacing controllers in used machines, ensure you're installing components with matching software versions to avoid compatibility issues. Clear codes and perform a test cycle under load.

---

Disclaimer: This guide provides general diagnostic procedures for Komatsu PC110-8M0 excavators. Always consult the official Komatsu service manual for your machine's serial number range and consider engaging a certified Komatsu technician for complex electrical diagnostics, especially when dealing with controller replacement or CAN bus network repairs.