Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
When there is an open in the driver inflator module or the SIR coil assembly the resistance between "Driver Side High" terminal "B9" and "Driver Side Low" terminal "B8" increases. This causes a larger voltage drop from the "Driver Side High" to the "Driver Side Low" across a resistor inside the DERM which connects these two terminals together. The increase in the voltage difference between "Driver Side High" and "Driver Side Low" is detected by the DERM during the "Continuous Monitoring" tests and DTC 26 is set.

DTC WILL SET WHEN
The voltage difference between "Driver Side High" terminal "B9" and "Driver Side Low" terminal "B8" is above or equal to a specified value for 500 milliseconds.

ACTION TAKEN
DERM sets a diagnostic trouble code and sends a command to the instrument cluster to turn "ON" the "AIR BAG" warning lamp.

DTC WILL CLEAR WHEN
The voltage difference between "Driver Side High" terminal "B9" and "Driver Side Low" terminal "B8" is below a specified value for 500 milliseconds.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks whether the DERM has set the diagnostic trouble code falsely.
2. This test determines whether the malfunction is in the driver inflator module or the SIR coil assembly.

DIAGNOSTIC AIDS
This diagnostic trouble code will only set when there is an improper connection of either the yellow 2-way connector near the base of the steering column or the yellow 2-way connector at the top of the steering column, an open SIR coil assembly or an open driver inflator module.