TIAGO

SUPPLEMENTARY RESTRAINT SYSTEM (SRS) 9 11.1.6.2. RESTRAINT WITH AIRBAGS 11.1.6.2.1. ECU The SRS ECU gets power supply from vehicle battery and is designed to perform the following functions in the air bag system: FUNCTIONS ENERGY RESERVE SRS ECU maintains a Reserve energy supply to provide deployment energy after ignition voltage is lost only during crash. However, the energy reserve is for a limited and short duration, therefore battery terminals and its connection to airbag ECU needs to be checked. CRASH DETECTION SRS ECU monitors vehicle deceleration levels to detect crashes which are severe enough to warrant deployment. AIR BAG DEPLOYMENT When sensors detect a frontal crash of sufficient severity, and send signals to the SRS ECU which in turn take deployment decision and causes enough current to flow to the air bag (inflator) modules to deploy them. LAMP CONTROL AFTER FIRST CRASH: “AIR BAG” warning lamp is turned and kept ON. Reset this memory mode using diagnostic tester. ECU needs replacement if it has sensed a crash. Once Airbag firing signal is given, ECU cannot be reset using diagnostic tester. MALFUNCTION DETECTION The SRS ECU performs diagnostic monitoring of the air bag system electrical components and switches on the indication on instrument cluster and sets a diagnostic trouble code when a malfunction is detected. MALFUNCTION DIAGNOSIS SRS ECU displays air bag diagnostic trouble codes and system status information through the use of diagnostic tool. “AIR BAG” WARNING LAMP A warning indicator in instrument cluster will alert for any malfunction of the airbag “SRS”. Under normal/ fault free condition, the air bag warning light comes “ON” for approximately 3 seconds and goes “OFF” when ignition is turned ON. LOCATION Airbag ECU is mounted on the floor tunnel along the centre line of the vehicle under the floor console.