Ford Grand Marquis Owner's Manual page 118

3. Press one button on each of the transmitters
to be programmed. Each transmitter button
must be pressed within seven (7) seconds of
the prior one. Each time a transmitter is
successfully programmed, all of the vehicle
doors will lock and then unlock to verify
programming. If the doors did not
lock/unlock, your transmitter was not
programmed.
Additional transmitters may be purchased from
your dealer (remote entry system will work with
up to four transmitters). Follow the same
programming procedure as above.
THIS DEVICE COMPLIES WITH PART 15 OF
THE FCC RULES. OPERATION IS SUBJECT
TO THE FOLLOWING TWO CONDITIONS:
(1) THIS DEVICE MAY NOT CAUSE
HARMFUL INTERFERENCE, AND (2) THIS
DEVICE MUST ACCEPT ANY
INTERFERENCE RECEIVED, INCLUDING
INTERFERENCE THAT MAY CAUSE
UNDESIRED OPERATION.
NOTE: All transmitters to be used on your
vehicle must be
programmed/reprogrammed at the same
time.
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