Ford SRS Description & Operation
  1. Manuals
  2. Brands
  3. Ford Manuals
  4. Automobile Accessories
  5. SRS
  6. Description & operation
Ford SRS Description & Operation

Ford SRS Description & Operation

Air bag restraint systems
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
DESCRIPTION & OPERATION
WARNING:
Accidental air bag deployment is possible. Personal injury may result.
Read and follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS
before working on air bag system or related components.
The Supplemental Restraint System (SRS), also known as air bag system, is designed to provide increased
accident protection for driver and passenger by deploying air bags and seat belt pretensioners in a front-end
collision. The air bags and pretensioners deploy in about 40 milliseconds after impact sensors close. Air bag
system is designed to be used with 3-point seat belts.
During a front-end collision, the air bag Electronic Crash Sensor (ECS) discriminates between an event that
warrants air bag deployment and an event that does not. In a crash of sufficient force, the ECS signals the air
bag modules and pretensioners to simultaneously deploy.
Air bag system includes following components: Electronic Crash Sensor (ECS) (also known as air bag
diagnostic monitor), a safing sensor (located inside the ECS), a back-up power supply (also located inside the
ECS), driver-side air bag module, passenger-side air bag module, Passenger-Side Air Bag Deactivation (PAD)
switch, left and right-side front seat belt pretensioners, AIR BAG warning light, clockspring (or sliding contact)
and associated wiring harnesses. See COMPONENT LOCATIONS .
BACK-UP POWER SUPPLY
A back-up power supply is lo inside Electronic Crash Sensor (ECS). If battery or battery cables are damaged in
a collision before sensor circuits close, back-up power supply will provide electrical power to deploy air bags.
Back-up power supply will hold a deployment charge for approximately one minute after negative battery cable
is disconnected.
CLOCKSPRING
The clockspring is a contact and wire assembly used to transfer electrical signals from steering column wiring
harness to driver-side air bag module.
DRIVER-SIDE AIR BAG MODULE
When sensors close, signaling an impact, ignitor triggers inflator. During ignition, sodium azide reacts with
copper oxide, producing nitrogen gas, which inflates air bag.
When air bag deploys, tear-seams molded into steering wheel trim cover separate, allowing deployment of air
bag assembly. Driver-side air bag module is not serviceable and must be replaced as a complete assembly.
ELECTRONIC CRASH SENSOR (ECS)
2001 ACCESSORIES/SAFETY EQUIPMENT
Ford Motor Co. - Air Bag Restraint Systems

Advertisement

Table of Contents
loading

Related Manuals for Ford SRS

Summary of Contents for Ford SRS

  • Page 1 The Supplemental Restraint System (SRS), also known as air bag system, is designed to provide increased accident protection for driver and passenger by deploying air bags and seat belt pretensioners in a front-end collision.

  • Page 2: Component Locations

    ECS is located on center tunnel, under instrument panel. ECS contains a microcomputer, which monitors electrical system components and connections. ECS performs a system self-check of air bag system internal circuits every time ignition switch is turned to RUN position. ECS also energizes AIR BAG warning light during initial system self-check and whenever a fault is detected.
  • Page 3 Fig. 1: Locating Restraint System Components Courtesy of FORD MOTOR CO. SYSTEM OPERATION CHECK 1. When checking air bag system operation (also known as prove out system), and upon completion of each...

  • Page 4: Airbag System

    diagnostic test, check for faults in air bag system. To check system, turn ignition switch to RUN position. If AIR BAG warning light illuminates for 6 seconds and then goes out, air bag system is functioning properly and no fault exist. 2.

  • Page 5: Disabling System

    VEHICLE under DISPOSAL PROCEDURES. If vehicle is involved in collision in which center tunnel area is damaged, inspect ECS mounting bracket for deformation. If damaged, ECS must be replaced whether or not air bags have deployed. Additionally, ensure ECS mounting area is restored to its original condition. ADJUSTMENTS CLOCKSPRING CENTERING WARNING:...
  • Page 6 DIAGNOSTICS DISABLING PROCEDURE . Component Replacement Disabling Procedure This procedure should only be used when replacing air bag system components. 1. Record pre-set radio frequencies for reprogramming (if equipped). Disconnect negative battery cable. Wait at least one minute for back-up power supply to deplete stored energy. 2.
  • Page 7 3. Remove passenger-side air bag module. See PASSENGER-SIDE AIR BAG MODULE under REMOVAL & INSTALLATION. Connect Air Bag Simulator (418-F088-105-R0012) to passenger-side air bag vehicle harness connectors (in place of air bag). On models equipped with seat belt pretensioners, remove front seats. See FRONT SEAT . 4.
  • Page 8 pretensioner simulator on right pretensioner harness connector (in place of pretensioner). Repeat procedure for left pretensioner. On all models, connect negative battery cable. ACTIVATING SYSTEM WARNING: Seat belt-pretensioner malfunction is possible. Personal injury may result. Inspect shoulder seat belt guide cover for damage. If cover is damaged or will not remained closed, replace seat belt guide cover with new part.

  • Page 9: Disposal Procedures

    If zero-ohm jumper is used, a Light Flash Code (LFC) will be displayed. Fig. 2: Identifying Air Bag Simulator Courtesy of FORD MOTOR CO. DISPOSAL PROCEDURES NOTE: Before proceeding, see AIR BAG SAFETY PRECAUTIONS .
  • Page 10 If an undeployed air bag module or seat belt pretensioner is diagnosed as faulty, remove faulty device and return intact to Ford Motor Company for proper disposal. Return carton for warranty claim credit. Air bag must be packaged and shipped according to U.S. Department of Transportation procedures. Retain replacement packaging including label.
  • Page 11 20' (6.09 m) away from deployment area. Wear safety goggles and hearing protection during deployment procedure. 1. Before proceeding, See AIR BAG SAFETY PRECAUTIONS . Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Remove air bag modules. See REMOVAL & INSTALLATION . With air bag modules removed, cut air bag connector from wiring harness near air bag module.

  • Page 12: Removal And Installation

    POST-COLLISION INSPECTION When a vehicle has been involved in a collision, certain components of the passive restraint system must be inspected or replaced. See AIR BAG/SRS COMPONENT INSPECTION & REPLACEMENT TABLES article in the GENERAL INFORMATION section. REMOVAL & INSTALLATION...
  • Page 13 4. Remove key-in-ignition warning indicator switch from ignition switch lock cylinder housing. Separate clockspring electrical connectors from retaining bracket and disconnect from wiring harness. Separate clockspring wire harness from clips on steering column. Pry clockspring retaining clips loose and remove clockspring. Fig. 3: Securing Clockspring For Removal Courtesy of FORD MOTOR CO.
  • Page 14 Fig. 4: Removing Ignition Switch Lock Cylinder Courtesy of FORD MOTOR CO. Installation 1. If installing NEW clockspring, remove locking mechanism pull ring. If installing existing clockspring, remove tape applied during removal procedure. If clockspring rotor has moved or if unsure of clockspring rotor position, center clockspring.

  • Page 15: System Operation Check

    NOTE: Slight turning of clockspring is allowable during installation to properly align clockspring to steering column. 2. With flats of clockspring aligned to flats of steering column slide clockspring onto steering column shaft. Engage clockspring retaining clips. Route clockspring wire harness down side of steering column and into retainers.

  • Page 16: Front Seat

    ELECTRONIC CRASH SENSOR (ECS) WARNING: Improper air bag system operation is possible. Personal injury may result. ECS orientation is critical for proper air bag system operation. If ECS mounting and bracket have been damaged, ECS must be replaced even if air bags have not deployed.
  • Page 17 NOTE: Front seat anchor nuts and bolt must be tightened in specific order. 1. Position front seat in vehicle. Install front seat anchor nuts and bolt (DO NOT tighten at this time). Tighten rear anchor nuts to specification. See TORQUE SPECIFICATIONS . Tighten front anchor nuts to specification.
  • Page 18 Fig. 5: Identifying Bulkhead Electrical Connectors Courtesy of FORD MOTOR CO.

  • Page 20: Instrument Cluster

    Fig. 6: Identifying Junction Panel Fasteners Courtesy of FORD MOTOR CO. INSTRUMENT CLUSTER Removal & Installation 1. Before proceeding, See AIR BAG SAFETY PRECAUTIONS . Disconnect negative battery cable. Using Radio Removing Tool (T87P-19061-A), remove audio unit. Lower steering wheel.
  • Page 21 Fig. 7: Locating Instrument Cluster Finish Panel Retaining Bolts Courtesy of FORD MOTOR CO. PASSENGER-SIDE AIR BAG DEACTIVATE (PAD) SWITCH Removal 1. Before proceeding, See AIR BAG SAFETY PRECAUTIONS . Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Using Radio Removing Tool (T87P-19061-A), remove audio unit.
  • Page 22 Fig. 8: Locating Passenger-side Air Bag Deactivate Switch Screws Courtesy of FORD MOTOR CO. Installation 1. To install, reverse removal procedure. Connect negative battery cable. With air bag simulators installed at all deployable devices, perform system operation check. See SYSTEM OPERATION CHECK .
  • Page 23 Fig. 9: Removing Passenger-side Air Bag Module Courtesy of FORD MOTOR CO. Installation 1. Position passenger-side air bag module in instrument panel opening. Install air bag module retaining bolts. Tighten air bag module retaining bolts to specification. See TORQUE SPECIFICATIONS .

  • Page 24: Steering Wheel

    Removal (With Seat Integrated Restraints) Before proceeding, see AIR BAG SAFETY PRECAUTIONS . Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Remove appropriate front seat. See FRONT SEAT . Remove nut and buckle-pretensioner assembly. NOTE: When tightening seat belt buckle-pretensioner nut, ensure seat backrest pivot bolt does not turn with nut.

  • Page 25: Wire Repair

    1. Before proceeding, See AIR BAG SAFETY PRECAUTIONS . Ensure front wheels are in straight- ahead position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Remove driver-side air bag module. See DRIVER-SIDE AIR BAG MODULE . 2.

  • Page 26: Torque Specifications

    Fig. 10: Repairing & Waterproofing Wiring Connections Courtesy of FORD MOTOR CO. TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Ft. Lbs (N.m) Seat belt buckle-pretensioner nut 30 (40) guide nut 30 (40) lower anchor bolt 30 (40) retractor-pretensioner bolt 30 (40) Steering wheel bolt...

  • Page 27: Wiring Diagrams

    INCH Lbs. (N.m) Bulkhead connector screws 35-50 (4.0-5.6) ECS module bolts 106 (12) Driver-side air bag module screws 106 (12) GEM retaining screws 9 (1) Instrument cluster bolts 18-27 (2.0-3.0) Instrument cluster finish panel bolts 18-27 (2.0-3.0) Instrument panel fuse block bolts &...
  • Page 29 Fig. 11: Air Bag System Wiring Diagram (2001 Excursion-early Production) Courtesy of FORD MOTOR CO.
  • Page 31 Fig. 12: Air Bag System Wiring Diagram (2001 Excursion-late Production) Courtesy of FORD MOTOR CO.
  • Page 33 Fig. 13: Air Bag System Wiring Diagram (2001 F250, F350, F450 & F550 Super Duty-early Production) Courtesy of FORD MOTOR CO.
  • Page 35 Fig. 14: Air Bag System Wiring Diagram (2001 F250, F350, F450 & F550 Super Duty-late Production) Courtesy of FORD MOTOR CO.

Table of Contents