DTC 51

Circuit Description
The sensing and diagnostic module (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 per-formed 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
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.

When DTC 51 is set, the SDM turns on the AIRBAG indicator and records crash data.

DTC 51 will clear when the SDM is replaced. This code cannot be cleared with a scan tool.

Test Description
The numbers below refer to steps on the diagnostic table.
2. If there is no evidence of an impact, DTC 51 may have been set falsely.
5. Refer to the cautions below.

Steps 1 - 5:

DTC 51 - Deployment Commanded

CAUTION: The sensing and diagnostic module (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 airbags are not disconnected, do not begin service until 10 minutes have passed after disconnecting power to the SDM. Otherwise, injury could result.

CAUTION: During service procedures, be very careful when handling the SDM. Never strike or jar the SDM. Never power the supplemental inflatable restraints (SIR) 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.