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P0117 on Hyundai Sonata

Engine Coolant Temperature Sensor 1 Circuit Low

Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the Hyundai Sonata (2020–2026, 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)).

Verified OEM Telemetry & Field Repair Tree
Hyundai Sonata2020–2026
Hyundai Sonata
Sedan2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Sonata SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
High urgency level
Est. Repair Cost
$80 - $250 (DIY: $20 - $60)
Parts & Labor DIY
Check P0117 On Another Hyundai Model:
Diagnose P0117 on Specific Sonata Model Year:

1. Symptoms of P0117 on Hyundai Sonata

When the Engine Control Module (ECM/PCM) on your Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)) logs fault code P0117, drivers commonly observe:

Check Engine Light on on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Radiator radiator fans running constantly at high speed on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Temperature gauge pegged at maximum H or not reading on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Engine hard starting when cold (flooding from excess fuel) on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Poor gas mileage and rough idling on Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP))
Hyundai Sonata OBD-II Port Location
The 16-pin diagnostic connector is located Under driver side steering column. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Hyundai Sonata

Historical warranty claims and technical repair bulletins for Hyundai Sonata point to the following failure distribution:

55%
ECT sensor internal short to ground (Hyundai OEM Part)
25%
Short circuit to ground in ECT signal wiring harness (Hyundai OEM Part)
12%
Damaged, corroded, or water-contaminated ECT connector (Hyundai OEM Part)
8%
Faulty PCM / ECM analog input circuit (Hyundai OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Hyundai Sonata.

3. Step-by-Step DIY Repair Guide for Hyundai Sonata

01
Scan ECT Temperature Data

Read ECT live PID on scanner. If it reads 284°F (140°C) or higher with engine cold, a short to ground exists. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: OBD-II Scanner
02
Unplug ECT Sensor Connector

Unplug sensor connector while watching live data. If temperature drops to -40°F (-40°C), the sensor itself is shorted. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: OBD-II Scanner
03
Inspect Wiring Harness

If reading stays pegged at max with sensor unplugged, inspect harness for pinch points grounding against engine block. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Digital Multimeter
04
Replace Engine Coolant Temperature Sensor

Allow engine to cool, unscrew old ECT sensor from coolant crossover pipe or thermostat housing, install new OEM sensor with fresh thread sealant. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: 19mm Deep Socket, Ratchet, Coolant Catch Pan
05
Top off Coolant & Clear Codes

Bleed air from cooling system, clear DTCs, and verify normal temperature rise on live data. on the Hyundai Sonata equipped with 2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP).

Required Tool: Coolant Funnel Kit, OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Hyundai Sonata (P0117)

Prime Fast Delivery & Verified Fitment
Variable Valve Timing (VVT)

VVT Oil Control Solenoid Valve

4.6 / 5.0 (Direct Fit)

Restores accurate camshaft timing and oil pressure regulation on Hyundai Sonata.

$34 – $65 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Hyundai SonataVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Hyundai Sonata

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Hyundai Sonata:

4. Hyundai Sonata P0117 FAQs

What causes code P0117 to trigger on a Hyundai Sonata?

On the Hyundai Sonata (2.5L 4-Cyl (191HP) / 2.5L Turbo (N Line 290HP) / 2.0L Hybrid (192HP)), P0117 is most frequently caused by ECT sensor internal short to ground or Short circuit to ground in ECT signal wiring harness.

Where is the OBD-II port located on my Hyundai Sonata?

On the Hyundai Sonata, the 16-pin DLC diagnostic connector is located Under driver side steering column. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Hyundai Sonata with code P0117?

No. The ECU thinks the engine is at 280°F+ (overheating) and runs rich or disables cooling fan logic. Given that P0117 carries a High severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.