FORD 2015 Focus - Manual (Page 221)

Note: If a person adds electrical or
electronic accessories or components to the
vehicle, the accessories or components may
adversely affect the low voltage battery
performance and durability and may also
affect the performance of other electrical
systems in the vehicle.
For longer, trouble-free operation, keep the
top of the battery clean and dry. Also,
make certain the battery cables are always
tightly fastened to the battery terminals.
If you see any corrosion on the battery or
terminals, remove the cables from the
terminals and clean with a wire brush. You
can neutralize the acid with a solution of
baking soda and water.
When a battery replacement is required,
the battery should only be replaced with
a Ford recommended replacement battery
that matches the electrical requirements
of the vehicle.
Because your vehicle’s engine is
electronically-controlled by a computer,
some engine control settings are
maintained by power from the low voltage
battery. Some engine computer settings,
like the idle trim and fuel trim strategy,
optimize the driveability and performance
of the engine. Some other computer
settings, like the clock and radio station
presets, are also maintained in memory by
power from the low voltage battery. When
a technician disconnects and connects the
low voltage battery, these settings are
erased. Complete the following procedure
in order to restore the settings:
1. With the vehicle at a complete stop,
set the parking brake.
2. Shift the transmission into P.
3. Turn off all accessories.
4. Step on the brake pedal and start the
vehicle.
5. Run the engine until it reaches normal
operating temperature. While the
engine is warming up, complete the
following: Reset the clock. See Audio
System (page 273). Reset the power
windows bounce-back feature. See
Windows and Mirrors (page 85).
Reset the radio station presets. See
Audio System (page 273).
6. Allow the engine to idle for at least one
minute. If the engine turns off, step on
the accelerator to start the engine.
7. While the engine is running, step on the
brake pedal and shift the transmission
to N.
8. Allow the engine to run for at least one
minute by pressing on the accelerator
pedal.
9. Drive the vehicle at least 10 miles (16
kilometers) to completely relearn the
idle and fuel trim strategy.
Note: If you do not allow the engine to
relearn the idle and fuel trim strategy, the
idle quality of your vehicle may be adversely
affected until the engine computer
eventually relearns the idle trim and fuel
trim strategy.
Note: Always dispose of automotive
batteries in a responsible manner. Follow
your local authorized standards for disposal.
Call your local authorized recycling center
to find out more about recycling automotive
batteries.
Note: It is recommended that the negative
battery cable terminal be disconnected from
the battery if you plan to store your vehicle
for an extended period of time.
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Focus (CDH), enUSA, First Printing
Maintenance