B1620

DTC B1620 Internal SDM Fault

Circuit Diagram:

Circuit Description

When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform turn-on test to diagnose critical malfunctions within SDM itself.

DTC B1620 Will Set When

- The SDM does not implement diagnostic operation. In case of above, the wiring harness of SDM should be checked before replacing the SDM.

Troubleshooting

The sensing and diagnostic module (SDM) can maintain sufficient voltage to deploy the airbags and pretensioners for 1 minute after the ignition is OFF and the fuse has been removed. If the airbags and pretensioners are not disconnected, do not begin service until one minute has passed after disconnecting power to SDM. Otherwise, injury could result.
During service procedure, 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 arrow on the SDM must be point toward the front of the vehicle to ensure proper operation of the SIR. The SDM could be activated if it is powered when it is not rigidly attached to the vehicle, resulting in unexpected deployment and possible injury.