B1053

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
The SDM contains a sensing device which converts vehicle velocity changes to an electrical signal. The electrical signal generated is processed by the SDM and then compared to a value stored in memory. When the generated signal exceeds the stored value, additional signal processing is performed and the generated signals are compared to signals stored in memory. When two of the generated signals exceed the stored values, or when one of the generated signals exceeds the stored value and the internal SDM sensor closes, with loop faults present, the SDM will cause current to flow through the inflator modules deploying the air bags and causing DTC B1053 to set.

DTC WILL SET WHEN
The SDM detects a frontal crash, up to 30 degrees off the centerline of the vehicle, of sufficient force to warrant deployment of the air bags, with loop faults present.

ACTION TAKEN
SDM turns On the AIR BAG warning lamp, records "Crash Data," and sets a DTC B1053 and DTCs B1015, B1021, B1019 or 131025.

DTC WILL CLEAR WHEN
The fault condition is removed, DTC B1053 will remain an active and history DTC, regardless if the ignition switch is turned Off, or a Scan tool "Clear Codes" command is issued. The SDM must be replaced.

DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the diagnostic chart.

Step 1. If inflator modules have not deployed, DTC B1053 may have set falsely.
Step 2. If DTC B1053 has set with no signs of frontal impact, the diagnostic trouble code has set falsely.
Step 5. This test checks for an SDM malfunction setting the diagnostic trouble code.
Step 7. This test determines whether the diagnostic trouble code was set inadvertently during diagnosis.
Step 8. When a frontal crash has occurred, it is necessary to perform the indicated procedures to ensure the SIR system is fully functional.

DIAGNOSTIC AIDS
It is critical to diagnose all circuitry before replacing the SDM. If a malfunction still exists, the new SDM may be damaged.

When measurements are requested in this chart, use SA 91114NE DVM with correct terminal adapter from SA 9206Z. When a check for proper connection is requested, refer to "Intermittents and Poor Connections." Intermittent Problems
When a wire connector or terminal repair is requested, use the proper repair parts and refer to "Wiring Repair."

CAUTION: BE CAREFUL WHEN YOU HANDLE A SENSING AND DIAGNOSTIC MODULE (SDM). DO NOT STRIKE OR JOLT THE SDM. BEFORE APPLYING POWER TO THE SDM:

- REMOVE ANY DIRT, GREASE, ETC. FROM THE MOUNTING SURFACE.
- POSITION THE SDM HORIZONTALLY ON THE MOUNTING SURFACE.
- POINT THE ARROW ON THE SDM TOWARD THE FRONT OF THE VEHICLE.
- TIGHTEN ALL OF THE SDM FASTENERS AND SDM BRACKET FASTENERS TO THE SPECIFIED TORQUE VALUE.

FAILURE TO FOLLOW THE CORRECT PROCEDURES COULD CAUSE AIR BAG DEPLOYMENT PERSONAL INJURY OR UNNECESSARY SIR SYSTEM REPAIRS.

CAUTION: BEFORE PERFORMING DIAGNOSTICS, THE IGNITION SWITCH MUST BE IN THE "OFF" POSITION FOR 10 MINUTES (REFER TO DISABLING AND ENABLING PRECAUTIONS).