Applicable Systems
PC200 Excavator
Symptoms
Fuel temperature sensor reading abnormally high; ECM may adjust fuel delivery incorrectly.
Possible Causes
- Fuel temp sensor short to +5V supply
- Sensor internal open circuit
- Sensor connector corrosion
Troubleshooting Steps
- Step 1: Check fuel temp sensor voltage at key ON
Voltage 0.5-4.5V range - Step 2: Inspect sensor connector for corrosion
Connector clean - Step 3: Check signal wire for short to +5V
No short to +5V - Step 4: Replace fuel temp sensor if voltage high
New sensor voltage within range - Step 5: Clear code and verify fuel temp reading
Temperature reads normal
How to Reset
Clear via service monitor after sensor replacement.
Common Replacement Parts
- Fuel Temperature Sensor P/N: 621-06-18100
Frequently Asked Questions
- Q: Does fuel temperature affect engine operation?
Yes. ECM adjusts injection timing and fuel quantity based on fuel density which changes with temperature. Faulty sensor can cause rough running.
Source: truckmanualshub.com Komatsu PDF
Category: Heavy Equipment