What is Liebherr Excavator Fault Code E016?

Liebherr Fault Code E016 indicates a malfunction in the engine preheating system, specifically related to the glow plug relay circuit or individual glow plug failure. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects abnormal voltage, resistance, or current draw in the preheating circuit during the self-test sequence or startup attempt.

The preheating system is critical for reliable cold starts in diesel engines, particularly in Liebherr excavators operating in low-temperature environments. When E016 appears, the ECM has identified that one or more glow plugs are not reaching proper operating temperature, the glow plug relay has failed, or there's a circuit fault preventing adequate current flow. For used excavators, this code often surfaces due to accumulated wear on electrical components and connections that have endured thousands of heating cycles.

Common Symptoms

• Hard starting or extended cranking time, especially in cold weather conditions
• White or gray smoke from the exhaust during cold starts, indicating incomplete combustion
• Engine warning light illuminated on the operator display panel
• Rough idle immediately after startup until engine reaches normal operating temperature
• Error message displayed on the multi-function display specifically referencing preheating system fault

Potential Causes

The most common technical reasons for Code E016 on used Liebherr excavators include:

• Failed glow plugs due to carbon buildup, tip erosion, or internal element breakage after extended service life
• Faulty glow plug relay with burned or pitted contacts that cannot handle the high amperage draw
• Damaged wiring harness at known rub points near the engine block or cylinder head where vibration causes insulation wear
• Corroded electrical connectors at individual glow plug terminals or the main relay harness connection
• Low battery voltage preventing adequate current supply to energize glow plugs properly
• ECM software glitches or corrupted calibration files (less common but possible in older machines)

How to Troubleshoot and Fix Code E016

Step 1: Visual Inspection and Preliminary Checks Begin by inspecting the glow plug harness for visible damage, particularly where it routes along the valve cover. Check all electrical connectors for corrosion, moisture intrusion, or loose terminals. On used excavators, pay special attention to connector pins that may have backed out slightly due to vibration over time.

Step 2: Test Glow Plug Resistance Using a digital multimeter, disconnect each glow plug connector and measure resistance between the glow plug terminal and engine ground. Typical specifications range from 0.5 to 2.0 ohms per plug (consult your specific model's service manual). Any reading showing infinite resistance indicates a failed glow plug requiring replacement.

Step 3: Verify Relay Operation and Circuit Voltage Locate the glow plug relay (typically in the main fuse/relay panel). With the ignition in the preheat position, use your multimeter to confirm the relay receives 12V supply voltage and that it closes properly (you should hear an audible click). Measure voltage at the glow plug bus bar during preheating—it should read 10-12V DC. Low voltage suggests relay contact failure or excessive circuit resistance.

Step 4: Check Current Draw Using a clamp-style ammeter, measure total current draw during the preheat cycle. Compare against manufacturer specifications (usually 50-100 amps depending on cylinder count). Abnormally high current suggests a shorted glow plug; low current indicates open circuits or poor connections.

Step 5: Clear Code and Verify Repair After replacing faulty components, use Liebherr diagnostic software (LiDat or equivalent) to clear the fault code and perform a preheating system functional test. Monitor for code recurrence over several cold-start cycles.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Liebherr service manual for your specific excavator model and consider professional diagnostic assistance for complex electrical issues or if you're unfamiliar with high-current electrical systems.