Post-Collision Diagnosis & Repair
POST-COLLISION DIAGNOSISTo inspect and service the SRS after a collision (whether or not the air bags has deployed), perform the following steps.
1. SRS Diagnosis Unit Memory Check
(1) Connect the scan tool to the data link connector. When connecting the scan tool to a vehicle up to 1993 model, use the adapter harness supplied together.
Caution: Make certain that the ignition switch is at OFF when the scan tool is connected or disconnected.
(2) Read (and write down) all displayed diagnostic trouble codes.
NOTE: If the battery power supply has been disconnected or disrupted by the collision, the scan tool cannot communicate with the SRS diagnosis unit. Inspect and, if necessary, repair the body wiring harness before proceeding further.
(3) Read the service data (fault duration and how many times memories are erased) using the scan tool.
NOTE:
- Maximum stored period: 9999 minutes (approximately 7 days)
- Maximum number of times to be stored: 250
(4) Erase the diagnostic trouble codes and after waiting 45 seconds or more read (and write down) all displayed diagnostic trouble codes.
2. Repair Procedure
When air bag deploys from collision
(1) Replace the following parts with new ones.
- Front impact sensors
- SRS diagnosis unit
- Air bag module
(2) Check the following parts and replace if there are any malfunctions.
- Clock spring
- Steering wheel, steering column and intermediate joint
1) Check wiring harness (built into steering wheel) and connectors for damage, and terminals for deformities.
2) Install air bag module to check fit or alignment with steering wheel.
3) Check steering wheel for noise, binding or difficult operation, or excessive free play.
(3) Check harnesses for binding, connectors for damage, poor connections, and terminals for deformities.
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.
Front Impact Sensors
(1) Check front upper frame lower for deformities or rust.
(2) Check front impact sensor for dents, cracks, deformities or rust.
(3) Check sensor harnesses for binds, connectors for damage, and terminals for deformities.
Fig. 12 Installing SRS Diagnosis Unit:
SRS Diagnosis Unit (SDU)
(1) Check SDU case and brackets for dents, cracks or deformities.
(2) Check connectors and lock lever for damage, and terminals for deformities.
Air Bag Module Driver's side
(1) Check pad cover for dents, cracks or deformities.
(2) Check for hooks and connectors damage, deformed terminal, and binding harness.
(3) Check air bag inflator case for dents, cracks or deformities.
(4) Install air bag module to steering wheel to check fit or alignment with the wheel.
Passenger's side
(1) Check module cover for dents, cracks or deformities.
(2) Check connectors for damage, terminals deformities and for binds.
(3) Check air bag inflator case for dents, cracks or deformities.
Clock Spring
(1) Check clock spring connectors and protective tube for damage, and terminals for deformities.
(2) Visually check the case and the gears for damage.
Steering Wheel, Steering Column and Intermediate Joint
(1) Check wiring harness (built into steering wheel) and connectors for damage, and terminals for deformities.
(2) Install air bag module to check fit or alignment with steering wheel.
(3) Check steering wheel for noise, binding or difficult operation, or excessive free play.
Harness Connector (Body and Front wiring harness)
1) Check for binding harnesses, connectors for damage, poorconnections, and deformed terminals.