FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Air Bag Systems

POST-COLLISION DIAGNOSIS
To inspect and service the SRS after a collision (whether or not the air bags have deployed), perform the following steps.

SRS-ECU MEMORY CHECK

Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.




1. Connect scan tool MB991958 to the data link connector (16-pin).

NOTE: If the battery power supply has been disconnected or disrupted by the collision, scan tool MB991958 cannot communicate with the SRS-ECU. Check the battery then check and, if necessary, repair the front wiring harness and the instrument panel wiring harness before proceeding.

2. Read (and write down) all displayed DTC (Refer to Diagnostic Trouble Code Chart). Diagnostic Trouble Code Descriptions




3. Read the data list (fault duration and how many times memories are erased) using scan tool MB991958.
4. Erase the DTC and, after waiting five seconds or more, read (and write down) all displayed DTC (Refer to Diagnostic Trouble Code Chart). Diagnostic Trouble Code Descriptions

REPAIR PROCEDURE

WHEN FRONT AIR BAGS DEPLOY IN A COLLISION.
1. Replace the following parts with new ones.
- SRS-ECU.
- Air bag modules (driver's and front passenger's).

2. Check the following parts and replace if there are any malfunctions.
- Clock spring.
- Steering wheel, steering column and intermediate joint
1. Check the wiring harness (built into the steering wheel) and connectors for damage, and terminals for deformation.
2. Install the air bag module to check fit or alignment with the steering wheel.
3. Check the steering wheel for noise, binds or difficult operation and excessive free play.
4. Check the collision energy absorbing mechanism on the steering column shaft (Refer to On-Vehicle Service - Steering Column Shaft Assembly Shock Absorbing Mechanism Check).

3. Check the wiring harnesses for binding, the connectors for damage, poor connections, and the terminals for deformation.

WHEN SIDE-AIRBAG DEPLOYS IN A COLLISION.
1. Replace the following parts with new ones.
- SRS-ECU.
- Side impact sensors.
- Front seat back assembly (Refer to Front Seat).

2. Check the wiring harnesses for binding, the connectors for damage, poor connections, and the terminals for deformation.

WHEN AIR BAG DOES NOT DEPLOY IN LOW-SPEED COLLISION.
Check the SRS components. If the SRS components are showing any visible damage such as dents, cracks, or deformation, replace them with new ones. Concerning parts removed for inspection, replacement with new parts and cautionary points for working, refer to appropriate INDIVIDUAL COMPONENT SERVICE.

SRS-ECU




1. Check the SRS-ECU case and brackets for dents, cracks or deformation.
2. Check the connector for damage, and the terminals for deformation.

AIR BAG MODULES




1. Check the pad cover for dents, cracks or deformation.
2. Check the connector for damage, terminals deformities, and the harness for binding.
3. Check the air bag inflator case for dents, cracks or deformities.
4. Install the driver's air bag module to the steering wheel to check fit or alignment with the steering wheel.
5. Install the passenger's (front) air bag module to the instrument panel and crossmember to check fit or alignment.
6. Install the passenger's (front) air bag module cover to the instrument panel to check fit or alignment.

FRONT SEAT BACK ASSEMBLY (SIDE-AIRBAG MODULE)




1. Check air bag module deployment section for dents or deformation.
2. Check that there is no connector damage, bent terminals or clamping of the harness.

CLOCK SPRING




1. Check the clock spring connectors and protective tube for damage, and the terminals for deformation.
2. Visually check the case for damage.

SIDE IMPACT SENSOR

NOTE: The illustration at left shows the side impact sensor (LH). The position of the side impact sensor (RH) is symmetrical to this.







1. Check that there is no bending or corrosion in the center pillar.
2. Check that there is no denting, breakage or bending of the side impact sensor.
3. Check that there is no clamping of the harness, connector damage or bent terminals.

STEERING WHEEL, STEERING COLUMN AND INTERMEDIATE JOINT
1. Check the wiring harness (built into the steering wheel) and the connectors for damage, and the terminals for deformation.
2. Install the air bag module to check fit or alignment with the steering wheel.
3. Check the steering wheel for noise, binding or difficult operation and excessive free play.
4. Check the collision energy absorbing mechanism on the steering column shaft.(Refer to On-Vehicle Service - Steering Column Shaft Assembly Shock Absorbing Mechanism Check).

HARNESS CONNECTOR
Check the harnesses for binding, the connectors for damage, poor connection, and the terminals for deformation.