P0117
Engine Coolant Temperature Sensor Circuit 1 Low Input
Description
Engine Coolant Temperature Sensor Circuit 1 Low Input. This powertrain diagnostic trouble code covers the engine, the fuel and ignition systems, emission control and the transmission.
OBD Codes Details
Possible Causes
Faulty sensor, intake leak, clogged fuel filter, weak fuel pump, damaged wiring
Solution
Check for intake leaks, inspect and clean the sensor, measure fuel pressure, compare live data against the expected range
Symptoms
- Check engine light illuminated
- Cooling fans running constantly
- Engine running rich, poor fuel economy
- Inaccurate temperature gauge reading
- Difficulty starting when engine is cold
Diagnostic Recommendations
- Inspect ECT sensor wiring for a short to ground
- Check ECT sensor connector for corrosion
- Test ECT sensor resistance at known coolant temperatures
- Verify coolant level and condition
- Replace ECT sensor if resistance readings are incorrect
Repair Cost Estimate
- ECT sensor replacement: $20-100
- Wiring repair: $80-200
- Coolant top-off/flush: $50-150
- Diagnostic scan: $80-150
- Total diagnostic and repair: $100-450
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Fact-checking completed
Verified by:
Pavel Volkov
Created:
Information verified against official sources
Official Sources
Society of Automotive Engineers
Official OBD-II diagnostic trouble codes standard (SAE J2012)
Automotive engineering standards organization
International Organization for Standardization
International standard for vehicle diagnostic systems
International standards for automotive diagnostics
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