P0440 GMC Terrain
EVAP System Malfunction · Powertrain Code · Low · Repair: Easy
What is P0440?
General EVAP (evaporative emission control) system malfunction. The system that prevents fuel vapors from escaping has detected a fault.
When the GMC Terrain triggers code P0440 (evap system malfunction), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the GMC Terrain.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your GMC Terrain.
Common Causes on GMC Terrain
- Loose, damaged, or missing gas cap
- Failed EVAP vent solenoid (extremely common on GM trucks)
- Cracked or disconnected EVAP system hose
- Failed EVAP purge solenoid
- Cracked charcoal canister
Symptoms
- Check Engine Light on
- Fuel smell near the vehicle
- No driveability symptoms in most cases
Notes for GMC Terrain
The EVAP vent solenoid on GM trucks is located near the charcoal canister under the vehicle — it is the single most common cause of EVAP codes on GM trucks.
