B1657
DTC B1657 Crash Recorded in Belt PretensionerCircuit 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.
In case of belt pretensioner explosion without front airbag inflation due to insufficient impact, replace the exploded belt pretensioner and remove the defect code using scan tool. In case, the belt pretensioner explosion counts over 5, then the SDM should also be replaced.
DTC B1657 Will Set When
- The history of belt pretensioner explosion is in 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.