Circuit Description
When the ignition switch is turned ON and during vehicle operation, the SDM
performs test to detect system faults. One test the SDM performs is to monitor the
driver deployment loop high circuit and driver deployment loop low circuit voltage
difference. By monitoring voltage difference, the SDM is able to calculate the driver
loop resistance. High resistance indicates an open somewhere in the driver deployment
loop.
DTC Parameters
DTC B0026 can be set when the driver loop resistance is high. The following
conditions must be met to set this DTC:
| • | Ignition voltage is present at the SDM and continuous. |
| • | The driver deployment loop resistance is over 4.8 ohms OR circuit 347
under 2.4 volts with loop resistance over 6 ohms. |
| • | Fault is present for half a second. |
Action Taken
| • | The air bag telltale will be ON. |
Diagnostic Aids
| • | When attempting to diagnose an intermittent driver loop fault, use the
scan tool to monitor current DTCs. Wiggle wires, turn steering wheel, and check
connections while watching for a current DTC to appear and/or disappear on the scan
tool. |
| • | Always start diagnosis of SIR DTCs with an inspection of wiring and components
for visible damage. |
| • | An open in circuits 347 or 348 to the driver inflator module could cause
this DTC. |
