Air Bag Supplemental Restraint System (SRS)

AIR BAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

Air Bag Supplemental Restraint System (SRS) Components:

The air bag supplemental restraint system (SRS) is designed to provide increased collision protection for front seat occupants in addition to that provided by the three-point safety belt system. Safety belt use is necessary to obtain the best occupant protection and to receive the full advantages of the SRS.

Driver Air Bag Module
The driver air bag module:
- is steering wheel mounted.
- will deploy upon receiving a signal from the RCM.
- has no subassemblies.

Clockspring
The clockspring:
- is mounted on the steering column, behind the steering wheel.
- provides a continuous electrical path from the RCM to the driver air bag module.

Passenger Air Bag Module
The passenger air bag module:
- is installed as an assembly.
- is mounted in the passenger side of the instrument panel.

Passenger Air Bag Deactivation (PAD) Switch
The passenger air bag deactivation (PAD) switch:
- is present on regular cab and SuperCab vehicles only.
- is located on the instrument panel to the right of the climate controls.
- contains a light emitting diode (LED) that indicates when the PAD switch is activated (passenger air bag disabled).
- allows the passenger air bag deployment circuit to be disabled using the ignition key.
- should be used whenever a child safety seat is being used in the front passenger seating position.

Restraints Control Module (RCM)

NOTE: When a new RCM is first installed in the vehicle, module configuration must be carried out.

If the RCM is incorrectly configured, erroneous DTC(s) will result. The RCM is mounted on the center tunnel under the instrument panel. The RCM:
- signals the inflators to deploy the air bags in the event of a deployable crash.
- monitors the air bag SRS for faults.
- illuminates the air bag indicator if a fault is detected.
- flashes the air bag indicator to indicate the lamp fault code (LFC) detected.
- communicates through the data link connector (DLC) the current or historical diagnostic trouble codes (DTCs).
- signals the instrument cluster to activate a chime if the air bag indicator is not available and another SRS fault exists.
- contains internal sensors which are not serviced separately.

The RCM monitors the SRS for possible faults. If a fault is detected while the ignition switch is in the RUN position, the RCM will illuminate the air bag indicator located in the instrument cluster.

When the ignition is cycled (turned OFF and then ON), the air bag indicator will remain lit for 6 seconds and then go out. If an SRS fault exists, the air bag indicator will then flash the 2-digit LFC. The air bag indicator will flash the LFC 5 times, then it will remain illuminated for the rest of the key cycle. The RCM will also communicate the current and historical DTCs through the data link connector (DLC), using the diagnostic tool. If the air bag indicator does not function, and the system detects a fault condition, the RCM will signal the instrument cluster to activate an audible chime. The chime is a series of 5 sets of 5 tone bursts. If the chime is heard, the SRS and the air bag indicator require repair.

LFCs are prioritized. If 2 or more faults occur at the same time, the fault having the highest priority will be displayed first. After that fault has been corrected, the next highest priority fault will be displayed.

The RCM includes a backup power supply. This feature provides sufficient backup power to deploy the air bags in the event that the ignition circuit is damaged in a collision before air bag sensors determine that an air bag deployment is activated. The backup power supply will deplete its stored energy approximately 1 minute after ignition power is removed from the RCM.

Electrical System
The SRS electrical system:
- is powered from the battery through the ignition circuit.
- provides the electrical path from the RCM to the SRS components.
- provides the electrical path from the RCM to the air bag indicator.
- provides the electrical path from the RCM to the data link connector (DLC).
- provides the electrical path from the RCM to the instrument cluster.

Impact Sensors
For this vehicle, the SRS contains sensors which are integral to the RCM and are not serviceable.