Operation CHARM: Car repair manuals for everyone.

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.