B1036

Circuit Description
When you first turn the ignition switch to the RUN position, the supplemental restraint sensing and diagnostic module (SDM) performs tests in order to diagnose critical malfunctions within itself. The SDM measures the following circuits in order to ensure that they are within their respective normal voltage ranges:
- IGNITION 1
- 23 VLR
- Deployment loop voltage

Then, the SDM performs the CONTINUOUS MONITORING test. The SDM contains a resistor network connected to 5 volts, ground, and to the SDM front-end sensor signal terminal 9. The SDM monitors two front end discriminating sensors that are wired in parallel. The 1.0 K OHM resistor in the LH supplemental restraint front end discriminating sensor parallel to the normally open switches in both sensors and provides a parallel path to ground. This causes a specified percentage of voltage to appear at the SDM front-end sensor signal input. The SDM monitors this voltage in order to detect shorts to power or an open discriminating sensor.

Conditions for Setting the DTC
- The SDM is configured for an supplemental restraint front end discriminating sensor.
- The voltage at the front-end sensor signal terminal 9 is more than 5.0 volts for 500 milliseconds.

The CONTINUOUS MONITORING test inspects for this DTC. This test occurs when IGNITION 1 is within the normal operating voltage range.

Action Taken When the DTC Sets
- The SDM sets a diagnostic trouble code.
- The SDM turns the AIR BAG warning lamp to the ON position.

Conditions for Clearing the DTC
- Current DTC
The voltage at front-end sensor signal terminal 9 is less than 3.2 volts for 500 milliseconds.
- History DTC
- You issue a scan tool CLEAR CODES command.
- After 250 malfunction free ignition cycles have occurred.

Diagnostic Aids
A broken or chafed wire in the supplemental restraint front end discriminating sensor circuit may cause an intermittent condition. Inspect CKT 1834and CKT 1851 carefully for cutting or chafing.
When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616-A Connector Test Adapter kit. When an inspection for proper connection is requested, refer to Intermittents and Poor Connections. When a wire, connector or terminal repair is requested, use J 38125-B Terminal Repair kit and refer to Wiring Repair.

Steps 1 - 4:

Steps 5 - 11:

Steps 12 - 17:

Steps 18 - 22:

Steps 23 - 27:

Steps 28 - 33:

Steps 34 - 39:

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This test inspects for proper contact or corrosion of the yellow 2-way connector.
7. This test inspects for a malfunctioning discriminating sensor.
8. This test inspects for an open in CKT 1851.
18. This test inspects for proper contact or corrosion of the supplemental restraint Sensing and Diagnostic Module (SDM) connector.
23. This test inspects for an open in CKT 1834.
33. This test isolates the open in CKT 1834 to one side of C109
36. This test inspects for a short to voltage in CKT 1834.