Nubira SX Hatchback L4-2.0L DOHC D-TEC MFI (1999)
Sensing and Diagnostic Module (SDM): Description and Operation
CAUTION: During service procedures, be careful when handling the SDM. Never shake or jar the SDM. Never apply power to the SIR system when
the
SDM is not rigidly attached to the vehicle. All SDM mounting bolts must be fully tightened. The arrow on the SDM must point toward the front of the
vehicle. Failure to follow these precautions could cause deployment and result in personal injury.
The SDM is located on the floor beneath the floor console assembly. The SDM performs the following functions:
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Monitors the supplemental inflatable restraint (SIR) system electrical components and sets a diagnostic trouble code (DTC) when a malfunction is
detected.
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Records any faults that are discovered.
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Displays SIR diagnostic trouble codes and system status information when connected to a scan tool.
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Illuminates the AIRBAG indicator to alert the driver to any faults.
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Provides a reserve power source to deploy the air - bags if an accident has disabled the normal power source.
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Monitors vehicle velocity changes to detect frontal impacts which are severe enough to warrant deployment.
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Causes current to flow through the airbag modules to cause deployment if a frontal impact of sufficient force is detected.
The SDM contains no user-serviceable parts.
