Chart C - Air Bag Warning Lamp Does Not Come on

CIRCUIT DESCRIPTION
When the ignition switch is turned On, IGN 1 voltage is applied to the AIR BAG telltale, Lamp Driver module and the Sensing and Diagnostic Module (SDM). The AIR BAG telltale is also connected to the SDM through the Lamp Driver module. When the ignition switch is turned from Off to On, the SDM flashes the AIR BAG telltale seven times. If there are no faults in the SIR system, the SDM will then turn off the AIR BAG telltale. The Lamp Driver module operates as the interface between the telltale and the SDM, switching circuit 358 to ground. Under normal operation circuit 358 is NOT GROUNDED and the AIR BAG telltale should be Off.

CHART TEST DESCRIPTION
The numbers below refer to the step numbers listed on the diagnostic chart.
Step 1. This step is to determine if other functions of the I/P cluster are also inoperative.
Step 2. This step is a check to see if the SDM is keeping the telltale Off.
Step 4. This step is an inspection of the IGN 1 fuse in the IPJB.
Step 6. This step replaces lamp driver with a jumper to turn On the telltale.
Step 7. This step checks for an open in circuit 39.
Step 10. This step checks the ground circuit lamp driver module.
Step 12. This step checks for a short to ground in circuit 358.
Step 14. This step is an inspection of the AIR BAG telltale.
Step 18. This step is a reminder to perform the Diagnostic System Check after completing all SIR system repairs. Diagnostic System Check

DIAGNOSTIC AIDS
An open in the "Ignition 1" fuse, circuit 358, or Lamp Driver module will keep the AIR BAG telltale from operating. A loose or burned out bulb is the most likely cause of this symptom, but not always easy to remove in this vehicle. If the AIR BAG telltale flashed seven times when turning ignition switch from Off to On, this chart will not be helpful.

Always perform the "SIR Diagnostic System Check" before using this charts.

When measurements are requested in this chart, use SA 91114NE digital multimeter with correct terminal adapter from SA 92O6Z. When a check for proper connection is requested, refer to "Intermittent and Poor Connections." When a wire connector or terminal repair is requested, use the proper repair parts and refer to "Wiring Repair." Intermittents and Poor Connections

NOTICE: Perform "SIR DIAGNOSTIC SYSTEM CHECK" before proceeding with this chart.

NOTE: Air bag telltale will flash seven times and remain On after the same DTC appears twice. After a fault is detected twice the DTC is stored in memory as a history code. If the air bag telltale is On, the DTC can be a current or history code.