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P0117 on Toyota RAV4

Engine Coolant Temperature Sensor 1 Circuit Low

Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the Toyota RAV4 (2020–2026, 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP).

Verified OEM Telemetry & Field Repair Tree
Toyota RAV42020–2026
Toyota RAV4
SUV2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
RAV4 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 Toyota Model:
Diagnose P0117 on Specific RAV4 Model Year:

1. Symptoms of P0117 on Toyota RAV4

When the Engine Control Module (ECM/PCM) on your Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP) logs fault code P0117, drivers commonly observe:

Check Engine Light on on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Radiator radiator fans running constantly at high speed on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Temperature gauge pegged at maximum H or not reading on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Engine hard starting when cold (flooding from excess fuel) on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Poor gas mileage and rough idling on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Toyota RAV4 OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell directly above brake pedal arm. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Toyota RAV4

Historical warranty claims and technical repair bulletins for Toyota RAV4 point to the following failure distribution:

55%
ECT sensor internal short to ground (Toyota OEM Part)
25%
Short circuit to ground in ECT signal wiring harness (Toyota OEM Part)
12%
Damaged, corroded, or water-contaminated ECT connector (Toyota OEM Part)
8%
Faulty PCM / ECM analog input circuit (Toyota OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Toyota RAV4.

3. Step-by-Step DIY Repair Guide for Toyota RAV4

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 Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

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 Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

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 Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

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 Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

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 Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

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

Equipment for Diagnosing Toyota RAV4 (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 Toyota RAV4.

$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 Toyota RAV4Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Toyota RAV4

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota RAV4:

4. Toyota RAV4 P0117 FAQs

What causes code P0117 to trigger on a Toyota RAV4?

On the Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP), 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 Toyota RAV4?

On the Toyota RAV4, the 16-pin DLC diagnostic connector is located Driver footwell directly above brake pedal arm. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Toyota RAV4 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.