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 Tool:
- MB991502: Scan tool (MUT-II)

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector (16-pin).
2. Read (and write down) all displayed diagnostic trouble codes.

NOTE: If the battery power supply has been disconnected or disrupted by the collision, scan tool MB991502 cannot communicate with the SRS-ECU. Check the battery then check and, if necessary repair the front wiring harness and the body wiring harness before proceeding.

3. Read the data list (fault duration and how many times memories are erased) using scan tool MB991502.

Data List:

4. Erase the diagnostic trouble codes and, after waiting five seconds or more, read (and write down) all displayed diagnostic trouble codes.

REPAIR PROCEDURE

WHEN FRONT AIR BAGS DEPLOY IN A COLLISION
1. Replace the following parts with new ones.
- SRS-ECU
- Air bag modules

2. Check the following parts and replace if there are any malfunctions.
- Clock spring
- Steering wheel, steering column and shaft assembly
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.

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

WHEN SIDE AIR BAGS DEPLOY IN A COLLISION
1. Replace the following parts with new ones.
- SRS-ECU
- Side impact sensors
- Front seatback assemblies (Refer to Front Seat Assembly.)

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

WHEN AIR BAGS DO 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 air bag module (driver's side) to the steering wheel to check fit or alignment with the steering wheel.
5. Install the air bag module (passenger's side) to the instrument panel and crossmember to check fit or alignment.




Front Seatback Assembly (Side-Airbag Module)
1. Check that there is no abnormality in the seat air bag module deployment section.
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
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.

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

Steering Wheel, Steering Column and Shaft Assembly
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.

Harness Connector (Instrument Panel Wiring Harness, and Floor Wiring Harness)
Check the harnesses for binding, the connectors for damage, poor connection, and the terminals for deformation.