GMC Terrain: Warning Lights, Gauges, and Indicators / Malfunction Indicator Lamp (Check Engine Light)

This light is part of the vehicle’s emission control on-board diagnostic system. If this light is on while the engine is running, a malfunction has been detected and the vehicle may require service. The light should come on to show that it is working when the ignition is in Service Mode. See Ignition Positions.

This light may also come on when the system has detected a problem with the Diesel Exhaust Fluid (DEF) management system. See Diesel Exhaust Fluid.

GMC Terrain. Malfunction Indicator Lamp (Check Engine Light)

Malfunctions are often indicated by the system before any problem is noticeable. Being aware of the light and seeking service promptly when it comes on may prevent damage.


If the vehicle is driven continually with this light on, the emission control system may not work as well, the fuel economy may be lower, and the vehicle may not run smoothly. This could lead to costly repairs that might not be covered by the vehicle warranty.


Modifications to the engine, transmission, exhaust, intake, or fuel system, or the use of replacement tires that do not meet the original tire specifications, can cause this light to come on. This could lead to costly repairs not covered by the vehicle warranty. This could also affect the vehicle’s ability to pass an Emissions Inspection/ Maintenance test. See Accessories and Modifications.

Light Flashing (Gasoline Engine Only)

If the light is flashing : A malfunction has been detected that could damage the emission control system and increase vehicle emissions. Diagnosis and service may be required.

To help prevent damage, reduce vehicle speed and avoid hard accelerations and uphill grades. If towing a trailer, reduce the amount of cargo being hauled as soon as possible.

If the light continues to flash, find a safe place to park. Turn the vehicle off and wait at least 10 seconds before restarting the engine. If the light is still flashing, follow the previous guidelines and see your dealer for service as soon as possible.

Light on Steady (All Engines)

If the light is on steady : A malfunction has been detected. Diagnosis and service may be required.

Check the following:

  • If fuel has been added to the vehicle using the capless funnel adapter, make sure that it has been removed. See “Filling the Tank with a Portable Gas Can” under Filling the Tank (Gasoline) or Filling the Tank (Diesel). The diagnostic system can detect if the adapter has been left installed in the vehicle, allowing fuel to evaporate into the atmosphere. A few driving trips with the adapter removed may turn off the light.
  • Poor fuel quality can cause inefficient engine operation and poor driveability, which may go away once the engine is warmed up. If this occurs, change the fuel brand. It may require at least one full tank of the proper fuel to turn the light off. See Recommended Fuel (LYX - 1.5L L4 Turbo Engine) or Recommended Fuel (LTG - 2.0L L4 Turbo Engine) or Fuel for Diesel Engines.

If the light remains on, see your dealer.

    Charging System Light

    The charging system light comes on briefly when the ignition is turned on, but the engine is not running, as a check to show the light is working. The light turns off when the engine is started...

    Emissions Inspection and Maintenance Programs

    If the vehicle requires an Emissions Inspection/Maintenance test, the test equipment will likely connect to the vehicle's Data Link Connector (DLC)...

    Other information:

    GMC Terrain 2018-2024 Owners Manual: Online Owner Center

    Online Owner Experience (U.S.) The GMC online owner experience is a one-stop resource that allows interaction with GMC and keeps important vehicle-specific information in one place. Membership Benefits : Download owner’s manuals and view vehicle-specific how-to videos...

    GMC Terrain 2018-2024 Owners Manual: Top Tether Anchor

    A top tether (3, 4) is used to secure the top of the child restraint to the vehicle. A top tether anchor is built into the vehicle. The top tether attachment hook (2) on the child restraint connects to the top tether anchor in the vehicle in order to reduce the forward movement and rotation of the child restraint during driving or in a crash...


      Engine Overheating

      The vehicle has an engine coolant temperature gauge on the instrument cluster and overheat messages in the Driver Information Center (DIC) to warn of engine overheating. See Engine Coolant Temperature Gauge.

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