GM Service Manual Online
For 1990-2009 cars only

The supplemental restraint system (SRS) Scan Tool Data Definitions contain a brief description of all SRS related parameters available on the scan tool. The list is in the order that the list appears on the scan tool.

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

Lamp Driver: The scan tool displays Internal or External. The warning lamp control method for a hard wired lamp is Internal. The warning lamp control method for a serial date controlled lamp is EXTERNAL.

Driver 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 and the 23 VLR voltages are within the normal ranges. Then the SDM sources a constant current to the driver deployment loop. The SDM then measures the voltage drop across the deployment loop and converts the measured voltage value to a driver deployment loop resistance value.

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 and 23 VLR voltages are within the normal ranges. Then the SDM sources a constant current to the passenger deployment loop. The SDM then measures the voltage drop across the deployment loop and converts the measured voltage value to a passenger deployment loop resistance value.

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

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

Driver VDIF: The scan tool displays 0-400 millivolts. The SDM measures the voltage difference between driver high and driver low and displays this voltage difference as Driver VDIF.

Passenger VDIF: The scan tool displays 0-400 Millivolts. The SDM measures the voltage difference between passenger high and driver low and displays this voltage difference as Passenger VDIF.

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

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

Warning Lamp ON: The scan tool displays 0-182 Hours. The SDM measures the continous warning lamp on time.

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

Driver Seatbelt: The scan tool displays Buckled or Unbuckled. The signal from the drivers seatbelt switch that the seatbelt is fastened.

Pass Air Bag Enable: The scan tool displays High or Low. The state of the Passenger Air Bag IP Module switch ON output.

Pass Air Bag Disable: The scan tool displays High or Low. The state of the Passenger Air Bag IP Module Switch OFF output.

Suppression Lamp Driver: The scan tool displays ON or OFF. The state of the Passenger Air Bag IP Module Switch OFF output driver.