P0117 on Subaru WRX
Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the Subaru WRX (2022–2026, 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI)).
1. Symptoms of P0117 on Subaru WRX
When the Engine Control Module (ECM/PCM) on your Subaru WRX (2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI)) logs fault code P0117, drivers commonly observe:
2. Most Likely Causes on Subaru WRX
Historical warranty claims and technical repair bulletins for Subaru WRX point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Subaru WRX
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 Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Unplug sensor connector while watching live data. If temperature drops to -40°F (-40°C), the sensor itself is shorted. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
If reading stays pegged at max with sensor unplugged, inspect harness for pinch points grounding against engine block. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
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 Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Bleed air from cooling system, clear DTCs, and verify normal temperature rise on live data. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Equipment for Diagnosing Subaru WRX (P0117)
VVT Oil Control Solenoid Valve
Restores accurate camshaft timing and oil pressure regulation on Subaru WRX.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Subaru WRX
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Subaru WRX:
4. Subaru WRX P0117 FAQs
What causes code P0117 to trigger on a Subaru WRX?
On the Subaru WRX (2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI)), 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 Subaru WRX?
On the Subaru WRX, the 16-pin DLC diagnostic connector is located Driver lower dash near fuse panel access door. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Subaru WRX 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.