What is Komatsu PC210LC-7 Fault Code E315?

Fault Code E315 on the Komatsu PC210LC-7 indicates a malfunction in the Engine Controller (ECM) communication circuit or a failure in the pump controller communication system. This diagnostic trouble code (DTC) specifically points to a disrupted data link between the engine control module and the hydraulic pump controller, preventing proper coordination between engine output and hydraulic demand.

This communication failure is critical for the PC210LC-7's performance because the ECM and pump controller must constantly exchange data to optimize fuel efficiency, match engine speed to hydraulic load, and maintain proper operating temperatures. When this circuit fails, the machine's intelligent control system cannot function properly, resulting in reduced productivity and potential component damage.

Common Symptoms

When Code E315 is active on your Komatsu PC210LC-7, operators typically experience:

• Engine warning light or action lamp illuminated on the instrument panel
• Reduced hydraulic power or sluggish attachment response, particularly during combined operations
• Engine derating or inability to reach maximum RPM under load
• Erratic engine speed fluctuations when engaging hydraulic functions
• Poor fuel economy due to loss of automatic engine-pump matching

Potential Causes

The most common technical reasons for E315 appearing on used PC210LC-7 excavators include:

• Corroded or loose connector pins at the ECM or pump controller harness connections (common failure point after 5,000+ hours)
• Damaged CAN bus wiring along the right-hand frame rail where harnesses experience vibration and rubbing against structural components
• Failed pump controller module due to heat exposure or internal component degradation
• ECM internal communication circuit failure, particularly in machines operated in high-dust environments
• Low battery voltage or poor grounding connections affecting signal integrity
• Water intrusion into controller enclosures from damaged seals or cab leaks

How to Troubleshoot and Fix Code E315

Step 1: Visual Inspection Begin by thoroughly inspecting all wiring harnesses between the ECM (located under the operator's seat) and the pump controller (mounted on the hydraulic pump). Look for chafed insulation, damaged connectors, or corrosion—especially at connection points. On used excavators, check for evidence of previous repairs or modified wiring that may compromise signal quality.

Step 2: Electrical Testing Using a digital multimeter, verify battery voltage is above 24V (for this model's electrical system). Check ground continuity at both controllers. With a Komatsu diagnostic software (KOMTRAX or compatible scan tool), monitor real-time communication status between modules while wiggling harness connections to identify intermittent failures.

Step 3: Connector Service Disconnect the 12-pin connector at the pump controller and the main ECM harness connector. Clean all pins with electrical contact cleaner and inspect for bent or pushed-back pins. Apply dielectric grease before reassembly—critical for preventing corrosion in used machines.

Step 4: Component Testing If connections test good, measure CAN-High and CAN-Low voltage (should be approximately 2.5V with key on, engine off). Resistance between CAN-High and CAN-Low should be approximately 60 ohms with all modules connected. Values outside this range indicate controller failure or harness short circuits.

Step 5: Controller Replacement If diagnostics confirm controller failure, replace the faulty unit with genuine Komatsu parts when possible. Aftermarket controllers may have compatibility issues with the PC210LC-7's specific software version.

Disclaimer: This guide provides general troubleshooting information. Complex electrical diagnostics should be performed by qualified technicians with proper Komatsu diagnostic equipment. Always consult the official Komatsu PC210LC-7 service manual and follow lockout/tagout procedures before performing electrical work.