GM Service Manual Online
For 1990-2009 cars only

The Scan Tool Data Definitions contain a short description of all SIR related parameters available on the scan tool. The list is in alphabetical order.

ADS: The scan tool displays Active or Inactive. The inflatable restraint forward discriminating sensor sends an Active signal to the SDM in order to show the SDM's state of readiness.

Coil Resistance: The scan tool displays 0-5 ohms. The SDM performs the resistance measurement test once each ignition cycle and verifies the SIR Contact Coil resistances are within the normal ranges.

Driver Bag Energy Reserve: The scan tool displays 0-25 volts. The SDM measures the internal reserve voltage available in order to activate the driver side deployment loop.

Driver Resistance: The scan tool displays 0-6.3 ohms. The SDM performs the resistance measurement test once each ignition cycle.After the resistance check, the SDM verifies the Ignition 1 voltage and the 23-volt loop reserve are within the normal ranges. At that time, the SDM supplies a constant current to the driver deployment loop. The SDM measures the voltage drop across the deployment loop and converts the measured voltage value to a deployment loop resistance value.

Driver Seat Belt: The scan tool displays Buckled or Unbuckled. The signal from the drivers seat-belt switch indicates that the seat belt is buckled.

Driver Senselo: The scan tool displays 0-20 volts. The SDM measures the low-side terminal voltage of the driver deployment loop, and the scan tool displays this voltage as Driver Senselo.

Driver VDIF: The scan tool displays 0-500 mV. The SDM measures the voltage difference between driver high and driver low circuits, and the scan tool displays this voltage difference as Driver VDIF.

Ignition: The scan tool displays 0-25.5 volts. The ignition represents the system voltage which is measured by the SDM at the SDM ignition feed.

Lamp Driver Feedback: The scan tool displays Active or Inactive. The warning lamp state is detected by the SDM.

Passenger Bag Energy Reserve: The scan tool displays 0-25 volts. The SDM measures the internal reserve voltage available in order to activate the passenger side deployment loop.

Passenger Resistance: The scan tool displays 0-6.3 ohms. The SDM performs the resistance measurement test once each ignition cycle and verifies the Ignition 1 voltage and 23-volt loop reserve are within the normal ranges. At that time, the SDM supplies a constant current to the passenger deployment loop. The SDM measures the voltage drop across the deployment loop and converts the measured voltage value to a resistance value of the passenger deployment loop.

Passenger Senselo: The scan tool displays 0-20 volts. The SDM measures the low-side terminal voltage of the passenger deployment loop, and the scan tool displays this voltage as Passenger Senselo.

Passenger VDIF: The scan tool displays 0-500 mV. The SDM measures the voltage difference between passenger high and passenger low circuits and displays this voltage difference as Passenger VDIF.

SIR System Type: The scan tool displays the type of deployment loops.

Warning Lamp Control: The scan tool displays ON or OFF. The warning lamp state is commanded by the SDM.

Warning Lamp Cycles: The scan tool displays 0-125 cycles. The ignition cycles of the current warning lamp state.