Introduction To Diagnosis

The SRS system is controlled by the SRS-ECU. The SRS-ECU judges how severe a collision is by detecting signals from the left and right front impact sensors and side impact sensors, front air bag analog G-sensor and front air bag safing G-sensor and side-airbag safing G-sensor. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the safing G-sensor is on, the SRS air bag will inflate. (The passenger's air bag may not inflate according to the occupant detection data from the occupant classification-ECU.) The SRS warning light in the combination meter alerts a malfunction of the SRS system. If the following symptoms occur even when the vehicle has not been in a collision, there may be a malfunction in the SRS system.

• The SRS warning light does not go off within approximately seven seconds after the ignition switch has been turned to the "ON" position.
• The SRS warning light does not illuminate when the ignition switch is turned to the "ON" position.

  Refer to Post-collision Diagnosis when inspecting and servicing a vehicle that has been in a collision (Refer to POST-COLLISION DIAGNOSIS  ).