B1026

Circuit Description
When you first turn the ignition switch to the RUN position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. Next the SDM measures IGNITION 1 voltage to make sure it is within its respective normal voltage range. Then the SDM proceeds with the DEPLOYMENT LOOP CONTINUITY test. During the DEPLOYMENT LOOP CONTINUITY test, the SDM measures the voltage difference between DRIVER SIDE HIGH and DRIVER SIDE LOW.

Conditions for Setting the DTC
^ The voltage difference between DRIVER SIDE HIGH terminal 2 and DRIVER SIDE LOW terminal 3 is more than or equal to 400 millivolts.
^ The malfunction must be present for at least 500 milliseconds during one of the following tests:

- DEPLOYMENT LOOP CONTINUITY
If the malfunction is detected in this test, the RESISTANCE MEASUREMENT test will not be performed.
- CONTINUOUS MONITORING

Action Taken When the DTC Sets
^ The SDM sets a DTC B1026.
^ The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC

^ Current DTC
The voltage difference between DRIVER SIDE HIGH terminal 2 and DRIVER SIDE LOW terminal 3 is less than 400 millivolts for 500 milliseconds.

^ History DTC
- You issue a scan tool CLEAR CODES command.
- Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids
The following can cause an intermittent condition:
^ A poor connection at the Inflatable Restraint Steering Wheel Module column connector terminal A and terminal B.
^ A poor connection at the upper Inflatable Restraint steering wheel coil connector terminal A and terminal B.
^ A poor connection at the SDM wiring harness connector terminal 2 and terminal 3.
^ An open in circuit 347.
^ An open in circuit 348.

An intermittent open in the Inflatable Restraint Steering Wheel Module Coil could also set this DTC. To test for a bad Inflatable Restraint Steering Wheel Module Coil, clear the DTC's, then turn the steering wheel back and forth with the ignition switch in the RUN position. If the AIR BAG warning lamp comes ON and DTC B1026 has set again, it is likely the Inflatable Restraint Steering Wheel Module Coil is malfunctioning.

When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616-A Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Diagrams / Testing for Electrical Intermittents. When a wire, connector or terminal repair is requested, use the J 38125-B Terminal Repair Kit.

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This step checks the driver deployment loop voltage difference that was measured by the Inflatable Restraint Sensing and Diagnostic Module (SDM).
3. This step checks to see if the Inflatable Restraint Steering Wheel Module Coil yellow 2-way connector is corroded or damaged.
10. This step isolates the malfunction to one side of the Inflatable Restraint Steering Wheel Module Coil yellow 2-way connector.
11. This step determines if there is a malfunctioning Inflatable Restraint Steering Wheel Module Coil or if there is a malfunctioning Inflatable Restraint Steering Wheel Module.
14. This step checks the SDM wiring harness connector for corrosion or damaged terminals.
19. This step checks to see if there is an open in circuit 347.
21. This step determines if there is an open in circuit 348 or if there is a malfunctioning SDM.