What is Komatsu PC160LC-7 Fault Code E-17?

Fault Code E-17 on the Komatsu PC160LC-7 indicates a malfunction in the machine's fuel injection system, specifically related to the fuel injection pump or its control circuit. This code is triggered when the Electronic Control Module (ECM) detects abnormal voltage, resistance, or signal inconsistencies from the injection pump controller or its associated wiring harness.

The PC160LC-7's SAA6D102E-2 engine relies on precise fuel delivery managed by electronic fuel injection components. When E-17 appears, the ECM cannot properly regulate fuel pressure or injection timing, which directly compromises engine performance, fuel efficiency, and emissions control. For used excavators, this code often points to age-related component degradation rather than catastrophic failure.

Common Symptoms

• Engine power loss or inability to reach full RPM under load
• Hard starting or extended cranking time, especially during cold starts
• Black or gray exhaust smoke indicating improper fuel combustion
• Engine warning light illuminated on the instrument cluster
• Erratic idle or engine stalling when throttling down from high RPM

Potential Causes

The most common triggers for E-17 on used PC160LC-7 excavators include:

• Fuel injection pump solenoid failure due to internal coil degradation (common after 6,000+ operating hours)
• Corroded or loose connectors at the injection pump harness, particularly at the pump-mounted controller plug
• Damaged wiring harness caused by rubbing against the engine block near the fuel filter mounting bracket (a known wear point on this model)
• ECM power supply issues including poor ground connections at the battery or starter terminals
• Contaminated fuel causing injection pump internal scoring or sticking components
• Failed ECM relay preventing proper voltage delivery to the fuel system

How to Troubleshoot and Fix Code E-17

Step 1: Visual Inspection
Begin by inspecting the injection pump wiring harness for obvious damage, particularly where it routes near the cylinder head and fuel filter. Check all connector pins for corrosion, bent terminals, or moisture intrusion. On used machines, pay special attention to wire insulation cracking from heat cycles.

Step 2: Electrical Testing
Using a digital multimeter, check voltage at the injection pump controller connector with the key on/engine off (should read 24V). Test solenoid resistance across the pump terminals (typically 3-5 ohms; consult your service manual). Abnormal readings indicate internal solenoid failure.

Step 3: Advanced Diagnostics
Connect Komatsu KOMTRAX or compatible diagnostic software to read real-time fuel system data. Monitor injection pump command signals versus actual performance. Check for intermittent connection issues by wiggling harnesses while monitoring live data.

Step 4: Component Replacement
If electrical tests confirm failure, replace the fuel injection pump assembly or solenoid valve depending on test results. For used excavators, always replace connector pigtails and apply dielectric grease to prevent future corrosion. Clear codes and perform a full-load test cycle.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu service manual for your specific serial number and consider professional diagnosis for complex fuel system repairs.