GMC Terrain 2025 - Page 95

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-18552429) - 2025
94 Instruments and Controls
Caution (Continued)
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 3223.
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.
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 3211. 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 3210.
If the light remains on, see your dealer.
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).
The DLC is under the instrument panel to the
left of the steering wheel. Connecting devices
that are not used to perform an Emissions
Inspection/Maintenance test or to service the
vehicle may affect vehicle operation. See Add-
On Electrical Equipment 3221. See your dealer
if assistance is needed.
The vehicle may not pass inspection if:
•
The light is on when the engine is running.
•
The light does not come on when the
ignition is on while the engine is off.
•
Critical emission control systems have
not been completely diagnosed. If this
happens, the vehicle would not be ready
for inspection and might require several
days of routine driving before the system is
ready for inspection. This can happen if the
12-volt battery has recently been replaced
or run down, or if the vehicle has been
recently serviced.