Steering Column: Description and Operation
STEERING COLUMN
This double tube type steering column has following three important features in addition to the steering function:
^ The column is energy absorbing type, designed to contract in a front-end collision.
^ The ignition switch and lock are mounted conveniently on this column.
^ With the column mounted lock, the ignition and steering operations can be locked to inhibit theft of the vehicle.
When the column assembly is removed from the vehicle, special care must be taken in handling it.
STEERING WHEEL AND DRIVER AIR BAG (INFLATOR) MODULE
The driver air bag (inflator) module is one of the supplemental inflatable restraint air bag system components and is mounted to the center of the steering wheel.
During certain frontal crashes, the air bag system supplements the restraint of the driver's and/or passenger's seat belts by deploying the air bag in each air bag (inflator) module.
The air bag (inflator) module should be handled with care to prevent accidental deployment.
When servicing, be sure to observe all WARNINGS and CAUTIONS.
SERVICE PRECAUTIONS
^ WARNING/CAUTION labels are attached on each part of air bag system components. Be sure to follow the instructions.
WARNING:
When performing service on or around air bag system components or air bag system wiring, follow the procedures listed to temporarily disable the air bag system. Refer to appropriate service manual procedures.
Failure to follow procedures could result in possible air bag deployment, personal in jury or unneeded air bag system repairs.
^ The Sensing and Diagnostic Module (SDM) in air bag system can maintain sufficient voltage to cause a deployment of air bag for up to 10 seconds after the ignition switch is turned to the "LOCK" position, the battery is disconnected or the fuse powering the SDM is removed. Therefore, wait for 10 seconds or more after the power to the SDM was turned "OFF" and before starting any operation on it.
Many of the service procedures require disconnection of the "AIR BAG" fuse and air bag (inflator) modules (driver and passenger) from the deployment loop to avoid an accidental deployment.
^ Never use air bag component parts from another vehicle.
^ If the vehicle will be exposed to temperatures over 93°C (200°F) (for example, during a paint baking process), remove the air bag system components.
^ When servicing, if shocks may be applied to air bag system component parts, remove those parts beforehand.
DISABLING AIR BAG SYSTEM
1. Turn steering wheel so that vehicle's wheels (front tires) are pointing straight ahead.
2. Turn ignition switch to "LOCK" position and remove key.
3. Remove "AIR BAG" fuse from the junction/fuse block.
4. Remove steering wheel side cap (left) and disconnect Yellow connector of driver air bag (inflator) module.
5. Pull out glove box while pushing its stopper from both right and left sides and disconnect Yellow connector of passenger air bag (inflator) module.
NOTE:
With "AIR BAG" fuse removed and ignition switch ON, "AIR BAG" warning lamp will be ON.
This is normal operation and does not indicate an air bag system malfunction.
ENABLING AIR BAG SYSTEM
1. Turn ignition switch to "LOCK" and remove key.
2. Connect Yellow connector of passenger airbag (inflator) module and Yellow connector of driver air bag (inflator) module respectively, and be sure to lock each connector with lock lever.
Fit each air bag (inflator) module connector onto each connector stay.
3. Install glove box and steering wheel side cap.
4. Install "AIR BAG" fuse to the junction/fuse block.
5. Turn ignition switch to "ON" and verify that "AIR BAG" warning lamp flashes 6 times and then turns off.
If it does not operate as described, perform AIR BAG DIAGNOSTIC SYSTEM CHECK.
HANDLING PRECAUTIONS
Live (Undeployed) Air Bag (Inflator) Module (Driver and Passenger)
WARNING: Never attempt to measure the resistance of the air bag (inflator) modules (driver and passenger). It is very dangerous as the electric current from the tester may deploy the air bag.
Special care is necessary when handling and storing a live (undeployed) air bag (inflator) module. The rapid gas generation produced during deployment of the air bag could cause the air bag (inflator) module, or an object in front of the air bag (inflator) module, to be thrown through the air in the unlikely event of an accidental deployment.
^ Never attempt disassembly of the air bag (inflator) module.
^ If any abnormality is found, be sure to replace it with new one as an assembly.
^ When an abnormality is noted as existing in the live (undeployed) air bag (inflator) module, be sure to deploy it before discarding it.
^ When grease, cleaning agent, oil water, etc. got on the air bag (inflator) modules (driver and passenger), wipe it off immediately with a dry cloth.
^ If air bag (inflator) module was dropped from a height of 91.4 cm (3 ft.) or more, it should be replaced.
WARNING:
^ For handling and storing an air bag (inflator) module, select a place where the ambient temperature below 65°C (150°F), without high humidity and away from electric noise.
^ When carrying a live air bag (inflator) module, make sure the bag opening is pointed away from you. In case of an accidental deployment, the bag will then deploy with minimal chance of injury. Never carry the air bag (inflator) module by the wires or connector on the underside of the module.
^ When placing a live air bag (inflator) module on a bench or other surface, always face the bag up, away from the surface. As the live passenger air bag (inflator) module must be placed with its bag (trim cover) facing up, place it on the workbench with a slit or use the workbench vise to hold it securely at its lower mounting bracket. If is also prohibited to place anything on top of the trim cover and stack air bag (inflator) modules. This is necessary so that a free space is provided to allow the air bag to expand in the unlikely event of accidental deployment.
Deployed Air Bag (Inflator) Module (Driver and Passenger)
WARNING:
^ Immediately after deployment, the air bag (inflator) module is very hot. Wait for at least 30 minutes to cool it off before starting servicing (handling) it.
^ Do not apply water, etc. to deployed air bag (inflator) module.
^ After an air bag (inflator) module has been deployed, the surface of the air bag may contain a powdery residue. This powder consists primarily of cornstarch (used to lubricate the bag as it inflates) and by-products of the chemical reaction. As with many service procedures, gloves and safety glasses should be worn.
^ Wash your hands with mild soap and water after completing the work.
Refer to the procedure described under DEPLOYED AIR BAG (INFLATOR) MODULE DISPOSAL.
Contact Coil and Combination Switch Assembly
Do not turn contact coil (on combination switch) more than allowable number of turns (about two and a half turns from the center position clockwise or counterclockwise respectively), or coil will break.
Air Bag Wire Harness and Connectors
CAUTION: When an open in air bag wire harness, damaged wire harness, connector or terminal is found, replace wire harness, connectors and terminals as an assembly.
^ Air bag wire harness can be identified easily as it is covered with a yellow protection tube. Be very careful when handling it.
^ When installing it, be careful so that the air bag wire harness is not caught or does not interfere with other parts.
^ Make sure all air bag system grounding points are clean and grounds are securely fastened for optimum metal-to metal contact. Poor grounding can cause intermittent problems that are difficult to diagnose.
DISPOSAL PRECAUTIONS
Do not dispose of live (undeployed) air bag (inflator) modules (driver and passenger). When disposal is necessary, be sure to deploy it first according to the procedure described.
WARNING: Failure to follow proper air bag (inflator) module disposal procedures can result in air bag deployment, which could cause personal injury. Undeployed air bag (inflator) modules must not be disposed of through normal refuse channels. The undeployed air bag (inflator) module contains substances that can cause severe illness or personal injury if the sealed container is damaged during disposal. Disposal in any manner inconsistent with proper procedures may be a violation of federal, state and/or local laws.