B1025

Circuit Description
When you first turn the ignition switch to the ON position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. Upon passing these tests IGNITION 1, 23 VLR and deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at DRIVER SIDE LOW terminal 10 and Passenger Side Low terminal 3 to detect shorts to B+ in the inflator module circuits. The service wait time is 10 minutes. Refer to Disabling the SIR System. Air Bag(s) Arming and Disarming

Conditions for Setting the DTC
^ The voltage at the Passenger Side Low terminal 3 is less than 3.5 volts.
^ The voltage at Driver Side Low terminal 10 is more than 3.5 volts for 500 milliseconds.

The Continuous Monitoring test checks this DTC. This test occurs when IGNITION 1 is within the normal operating voltage range.

Action Taken When the DTC Sets
^ The SDM sets DTC B1025 and also DTC B1071.
^ The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC
DTC B1025 is a latched code. You cannot clear a latched code. Repair the malfunction that set this DTC before you replace the SDM.

Diagnostic Aids
A short-to-B+ in the Inflatable Restraint Steering Wheel Module circuit may cause an intermittent condition. A DTC B1025 would be accompanied by DTC B1071. Inspect the GRN/RED wire and the GRN wire carefully for cut or chafed wires. A careful inspection of circuits and components indicated on the DTC B1025 Table is essential to make sure that replacement SDM will not be damaged. The diagnostic table directs the technician to note the entry value of DRIVER SENSELO. Comparing the value of DRIVER SENSELO can be helpful in determining if an intermittent condition exists.

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 a check 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.

DTC Table Test Description
Numbers below refer to step numbers on the diagnostic table.
2. This step determines the DRIVER SIDE LOW voltage measured by the Inflatable Restraint Sensing and Diagnostic Module (SDM).
3. This step isolates the malfunction to one side of the yellow 2-way connector on the Inflatable Restraint Steering Wheel Module Coil. This connector is located near the base of the steering column.
4. This step determines whether the malfunction is in the Inflatable Restraint Steering Wheel Module Coil or in the Inflatable Restraint Steering Wheel Module.
7. This step determines whether the malfunction is in the GRN/RED wire.
9. This step determines whether the malfunction is in the GRN wire.