Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
118
Instruments and Controls
If the light stays on, or comes
on while driving, there may be
a problem with the electrical
charging system. Have it
checked by your dealer.
Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
If a short distance must be
driven with the light on, be
sure to turn off all
accessories, such as the radio
and air conditioner. Find a safe
place to stop the vehicle.
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
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.
Caution
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
(Continued)
Caution (Continued)
costly repairs that might not
be covered by the vehicle
warranty.
Caution
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
If the light is flashing :
A
malfunction has been
detected that could damage
the emission control system