Exterior Mirrors; Convex Mirrors; Manual Mirrors - GMC Sierra 2500 HD 2024 Owner's Manual

34 Keys, Doors, and Windows
The security light, in the instrument cluster,
comes on if there is a problem with arming
or disarming the theft-deterrent system.
The system has one or more remote keys
matched to an immobilizer control unit in
your vehicle. Only a correctly matched
remote key will start the vehicle. If the
remote key is ever damaged, you may not
be able to start your vehicle.
When trying to start the vehicle, the
security light may come on briefly when the
ignition is turned on. If the engine does not
start and the security light stays on, there is
a problem with the system. Turn the
ignition off and try again.
If the vehicle will not change ignition modes
(accessory mode, on, off), and the remote
key appears to be undamaged, try another
remote key. Or, you may try placing the
remote key in the remote key pocket
located in the center console. See Remote
Key Operation 0 15.
If the ignition mode will not change with
the other remote key or with the remote
key in the remote key pocket, your vehicle
needs service. If the ignition does change
modes, the first remote key may be faulty.
See your dealer who can service the
theft-deterrent system and have a new
remote key programmed to the vehicle.
It is possible for the immobilizer system to
learn new or replacement remote keys. Up
to eight remote keys can be programmed
for the vehicle. To program additional
remote keys, see "Programming Remote
Keys to the Vehicle" under Remote Key
Operation 0 15.
Do not leave the remote key or device that
disarms or deactivates the vehicle theft
system in the vehicle.

Exterior Mirrors

Convex Mirrors

Warning
A convex mirror can make things, like
other vehicles, look farther away than
they really are. If you cut too sharply
into the right lane, you could hit a
vehicle on the right. Check the inside
mirror or glance over your shoulder
before changing lanes.
Standard Mirrors
If equipped, the passenger side mirror is
convex shaped. A convex mirror surface is
curved so more can be seen from the
driver seat.
Trailer-Tow Mirrors
The upper portion of both the driver and
passenger mirrors is flat.
The lower portion of both the driver and
passenger mirrors is convex. A convex mirror
surface is curved so more can be seen from
the driver seat. The lower portion is
adjusted manually.

Manual Mirrors

If equipped, adjust manual mirrors by
moving the mirror up and down or left to
right to see a little of the side of the vehicle
and to have a clear view behind the vehicle.
Using hood-mounted air deflectors and
add-on convex mirror attachments could
decrease mirror performance.