P0117 on GMC Sierra 1500
Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the GMC Sierra 1500 (2020–2026, 5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel).
1. Symptoms of P0117 on GMC Sierra 1500
When the Engine Control Module (ECM/PCM) on your GMC Sierra 1500 (5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel) logs fault code P0117, drivers commonly observe:
2. Most Likely Causes on GMC Sierra 1500
Historical warranty claims and technical repair bulletins for GMC Sierra 1500 point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for GMC Sierra 1500
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 GMC Sierra 1500 equipped with 5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel.
Unplug sensor connector while watching live data. If temperature drops to -40°F (-40°C), the sensor itself is shorted. on the GMC Sierra 1500 equipped with 5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel.
If reading stays pegged at max with sensor unplugged, inspect harness for pinch points grounding against engine block. on the GMC Sierra 1500 equipped with 5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel.
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 GMC Sierra 1500 equipped with 5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel.
Bleed air from cooling system, clear DTCs, and verify normal temperature rise on live data. on the GMC Sierra 1500 equipped with 5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel.
Equipment for Diagnosing GMC Sierra 1500 (P0117)
VVT Oil Control Solenoid Valve
Restores accurate camshaft timing and oil pressure regulation on GMC Sierra 1500.
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 GMC Sierra 1500
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the GMC Sierra 1500:
4. GMC Sierra 1500 P0117 FAQs
What causes code P0117 to trigger on a GMC Sierra 1500?
On the GMC Sierra 1500 (5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel), 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 GMC Sierra 1500?
On the GMC Sierra 1500, the 16-pin DLC diagnostic connector is located Under driver dashboard, left of 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 GMC Sierra 1500 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.

