DTC 51

Circuit Description
The sensing and diagnostic module (SDM) contains a sensing device which convents 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, the SDM will cause sufficient current to flow through the inflator modules to deploy the airbags and cause DTC 51 to be set.

DTC 51 Will Set When
The SDM detects a frontal crash within 30 degrees of the centerline of the vehicle, of sufficient force to warrant deployment of the airbags.

Action Taken
The SDM turns on the AIRBAG indicator, records crash data, and sets a DTC 51.

DTC 51 Will Clear When
The SDM is replaced. This code cannot be cleared with a scan tool.

Test Description
The number(s) below refer to step(s) on the diagnostic table.

2. If there is no evidence of impact, DTC may have been set falsely.
5. See the cautions below.

Steps 1 - 5:

DTC 51 - Deployment Commanded

CAUTION: The SDM can maintain sufficient voltage to deploy the airbags for 10 minutes after the ignition is OFF and the fuse has been removed. If the air - bags are not disconnected, service cannot begin until 10 minutes have passed after disconnecting power to the SDM.

CAUTION: During service procedures, be very careful when handling the SDM. Never strike or jar the SDM.

Never power up the SIR system when the SDM is not rigidly attached to the vehicle. All SDM mounting bolts must be carefully tightened, and the SDM arrow must be pointing toward the front of the vehicle to ensure proper operation of the SIR system. The SDM could be activated if it is powered when if is not rigidly attached to the vehicle, resulting in unexpected deployment and possible injury.