Circuit Description
When the ignition switch is turned on and during vehicle operation, the SDM
performs tests 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.
Conditions for Setting the DTC
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 cirucit
347 under 2.4 volts with loop resistance over 6 ohms. |
| • | The fault is present for half a second. |
Action Taken When the DTC Sets
| • | The air bag telltale will be on. |
Diagnostic Aids
| • | When attempting to diagnose an intermittent driver loop fault, use the
scan tool to monitor the current DTCs. Wiggle the wires, turn the steering wheel,
and check connections while watching for a current DTC to appear and/or disappear
on the scan tool. |
| • | Always start diagnosis of the 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. |
B0026
