P0117 on GMC: Symptoms, Causes & Fix
Official technical diagnostic wire for fault code P0117 specifically affecting GMC vehicles (Sierra 1500, Yukon, Acadia, Canyon, Terrain).
Select Your GMC Model for P0117:
1. Common Symptoms on GMC Vehicles
When GMC Engine Control Modules (ECM) trigger fault code P0117, drivers typically report:
2. Root Causes on GMC Engines
Historical diagnostic claims across GMC engines point to the following failure distribution:
3. Step-by-Step Fix Protocol for GMC
Read ECT live PID on scanner. If it reads 284°F (140°C) or higher with engine cold, a short to ground exists. on GMC engines.
Unplug sensor connector while watching live data. If temperature drops to -40°F (-40°C), the sensor itself is shorted. on GMC engines.
If reading stays pegged at max with sensor unplugged, inspect harness for pinch points grounding against engine block. on GMC engines.
Allow engine to cool, unscrew old ECT sensor from coolant crossover pipe or thermostat housing, install new OEM sensor with fresh thread sealant. on GMC engines.
Bleed air from cooling system, clear DTCs, and verify normal temperature rise on live data. on GMC engines.
Equipment for Diagnosing GMC (P0117)
VVT Oil Control Solenoid Valve
Restores accurate camshaft timing and oil pressure regulation on GMC.
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.
4. GMC P0117 Frequently Asked Questions
What does code P0117 mean on a GMC?
On GMC vehicles, P0117 indicates that the Engine Control Module (ECM) detected engine coolant temperature sensor 1 circuit low. This typically points to ECT sensor internal short to ground or Short circuit to ground in ECT signal wiring harness.
Can I continue driving my GMC with code P0117?
No. The ECU thinks the engine is at 280°F+ (overheating) and runs rich or disables cooling fan logic. Because this code carries a High severity rating on GMC powertrains, we recommend scanning live data values promptly to prevent secondary damage.
How much does it cost to fix code P0117 on a GMC?
Estimated DIY parts cost ranges from $80 - $250 (DIY: $20 - $60), while professional shop repairs at an authorized GMC dealership or independent specialist typically range from $180 to $380 including diagnostic labor.