2003 FORD FOCUS wiring

•Front safety belts with pretensioners, energy management retractors,
and safety belt usage sensors.
•Driver’s seat position sensor.
•Front crash severity sensor.
•Restraints Control Module (RCM) with impact and safing sensors.
•Restraint system warning light and back-up tone.
•The electrical wiring for the air bags, crash sensor(s), safety belt
pretensioners, front safety belt usage sensors, driver seat position
sensor, and indicator lights.
How does the personal safety system work?
The Personal Safety System can adapt the deployment strategy of your
vehicle’s safety devices according to crash severity and occupant
conditions. A collection of crash and occupant sensors provides
information to the Restraints Control Module (RCM). During a crash, the
RCM activates the safety belt pretensioners and/or either one or both
stages of the dual-stage air bag supplemental restraints based on crash
severity and occupant conditions.
The fact that the pretensioners or air bags did not activate for both front
seat occupants in a collision does not mean that something is wrong with
the system. Rather, it means the Personal Safety System determined the
accident conditions (crash severity, belt usage, etc.) were not
appropriate to activate these safety devices. Front air bags and
pretensioners are designed to activate only in frontal and near-frontal
collisions, not rollovers, side-impacts, or rear-impacts unless the collision
causes sufficient longitudinal deceleration.
Driver and passenger dual-stage air bag supplemental restraints
The dual-stage air bags offer the capability to tailor the level of air bag
inflation energy. A lower, less forceful energy level is provided for more
common, moderate-severity impacts. A higher energy level is used for
the most severe impacts. Refer toAir bag Supplemental Restraints
section in this chapter.
Front crash severity sensor
The front crash severity sensor enhances the ability to detect the
severity of an impact. Positioned up front, it provides valuable
information early in the crash event on the severity of the impact. This
allows your Personal Safety System to distinguish between different
levels of crash severity and modify the deployment strategy of the
dual-stage air bags and safety belt pretensioners.
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77

•diagnostic module.
•and the electrical wiring which connects the components.
The diagnostic module monitors its own internal circuits and the
supplemental air bag electrical system warning (including the impact
sensors), the system wiring, the air bag system readiness light, the air
bag back up power and the air bag ignitors.
Determining if the system is operational
The supplemental restraint system uses a warning indicator in the
instrument cluster or a back-up tone to indicate the condition of the
system. Refer to theWarning lightsection in theInstrument cluster
chapter. Routine maintenance of the air bag is not required.
A difficulty with the system is indicated by one or more of the following:
•The readiness light (same light
for front and side air bag system)
will either flash or stay lit.
•The readiness light will not
illuminate immediately after ignition is turned on.
•A series of five beeps will be heard. The tone pattern will repeat
periodically until the problem and/or light are repaired.
If any of these things happen, even intermittently, have the supplemental
restraint system serviced at your dealership or by a qualified technician
immediately. Unless serviced, the system may not function properly in
the event of a collision.
Side air bag system (if equipped)
Do not place objects or mount equipment on or near the air bag
cover on the side of the seatbacks of the front seats or in front
seat areas that may come into contact with a deploying air bag. Failure
to follow these instructions may increase the risk of personal injury in
the event of a collision.
Do not use accessory seat covers. The use of accessory seat
covers may prevent the deployment of the side air bags and
increase the risk of injury in an accident.
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93

SNOW TIRES AND CHAINS
Snow tires must be the same size and grade as the tires you
currently have on your vehicle.
The tires on your vehicle have all weather treads to provide traction in
rain and snow. However, in some climates, you may need to use snow
tires and chains. If you need to use chains, it is recommended that steel
wheels (of the same size and specifications) be used, as chains may chip
aluminum wheels.
Vehicles with Traction Control or AdvanceTrac
(if equipped) may
exhibit some unusual driving characteristics, when using snow chains,
which can be avoided by switching AdvanceTrac
off.
Follow these guidelines when using snow tires and chains:
Snow chains should only be fitted to size P 185/65 R14 tires.
Snow chains should never be used on the spare tire.
•Use only SAE Class S chains.
•Install chains securely, verifying that the chains do not touch any
wiring, brake lines or fuel lines.
•Drive cautiously. If you hear the chains rub or bang against your
vehicle, stop and re-tighten the chains. If this does not work, remove
the chains to prevent damage to your vehicle.
•If possible, avoid fully loading your vehicle.
•Remove the tire chains when they are no longer needed. Do not use
tire chains on dry roads.
•The suspension insulation and bumpers will help prevent vehicle
damage. Do not remove these components from your vehicle when
using snow tires and chains.
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