Code
P1114
GWM
P — Powertrain
- Coolant Temperature Sensor Circuit Low Voltage (ECT)
Views:
UK: 2
EN: 1
RU: 5
AI status
Completed
Completed
100%
Causes
- Short to ground in ECT signal circuit
- Failed (low-resistance) ECT sensor
- Corroded, damaged or disconnected connector at the sensor
- Damaged wiring (chafing, pinched, melted insulation) between sensor and ECM
- Incorrect or missing reference voltage from ECM (5 V reference fault)
- PCM/ECM internal fault or poor ground
Symptoms
- Check engine light (MIL) illuminated
- Engine runs poorly when cold or incorrect idle due to wrong temperature reading
- Extended open-loop operation or poor fuel economy
- Radiator fan or cooling control may behave incorrectly
- Heater not reaching expected temperature quickly
What to check
- Read freeze frame and live PID data for coolant temperature sensor voltage and temperature value
- Scan for related codes (P0115–P0119, P0125) and note conditions when code set
- Visually inspect sensor connector and wiring for corrosion, damage, loose pins or pinched areas
- Backprobe sensor connector with key ON and measure signal voltage and reference voltage
- Measure sensor resistance with sensor disconnected and compare to specification (at known coolant temp)
- Check ECM grounds and power supply fuses
Signal parameters
- Typical ECM reference (pull-up) voltage: ≈5.0 V (vehicle-specific)
- Expected ECT signal voltage (approximate): cold (~4.0–4.5 V), warm (~1.0–2.5 V) — values vary by design
- Low-voltage fault threshold: signal much lower than expected (often
- Typical NTC thermistor resistance examples (vehicle-specific): ~2–3 kΩ at 20 °C, several hundred ohms at 80 °C — confirm with manufacturer chart
Diagnostic algorithm
- Retrieve freeze-frame data and note ambient and engine temperatures when fault occurred.
- Visually inspect ECT sensor, connector and wiring harness for obvious damage, corrosion or contact with hot/moving parts. Repair as needed.
- With ignition ON (engine off) backprobe the sensor connector: verify reference voltage from ECM (~5 V) at the reference pin.
- Measure signal voltage at the sensor with key ON and with engine cold and warm. If voltage is very low (
- Disconnect the sensor and measure resistance between the sensor terminals. Compare resistance to known specification at the measured coolant temperature. Replace sensor if out of spec.
- If sensor resistance is normal but signal remains low when connected, inspect and continuity-test the signal wire to the ECM for short to ground. Repair wiring faults.
- Check ECM ground(s) and supply fuses; repair any poor grounds or blown fuses.
- If wiring and sensor pass tests but low input persists at the ECM connector, verify ECM reference and input circuits. Consider ECM bench/diagnostic tests or replace ECM if confirmed faulty.
- Clear code(s) after repairs and perform a cold/hot drive cycle to confirm the code does not return.
Likely causes
- ECT sensor has internally shorted or failed low-resistance
- Signal wire is shorted to chassis ground near sensor
- Connector terminals corroded or pushed out causing contact to ground
- Wire harness abrasion where it contacts body or engine components
- ECM reference/ground pin loose or corroded at connector
Fault status
Status
ECT circuit reported low-voltage input to the PCM. The PCM may use a default temperature value or enter fail-safe strategies (altered fuel/idle control) until the fault is resolved. Continued driving without repair can affect emissions, fuel economy and engine drivability.
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
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