When a vehicle crashes with a certain degree of frontal impact, the gas generator will ignited an electrical firing signal from the SRSCM (Supplemental Restraint System Control Module). Gas from the gas generator causes movement of the piston in the manifold case (cylinder), which operates the rack gear. The rack gear, rotates a piston gear and a pinion rotates the planet gears. Finally, the webbing is retracted by the rotation of the spool. Therefore, the pretensioner seat belt helps to reduce the severity of injury to the front seat occupant by retracting the seat belt webbing. This prevents the occupant from thrusting forward and hitting the steering wheel or the instrument panel when the vehicle crashes.
The DBPT squib circuit consists of the SRSCM and DBPT. If it causes the DBPT to deploy when the DBPT deployment conditions are satisfied. The above DTCs are recorded when the resistance too high is detected in the DBPT squib circuit.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Check resistance
? Contact resistance in DBPT circuit.
? Faulty DBPT.
? Faulty SRSCM.
Enable Conditions
? Ignition "ON"
Threshold Value
? DBPT resistance = 5.9 ?
? Tolerance band : 3.9 ? < Rs < 5.9 ?
Diagnostic Time
Qualification
? More than 2 sec
De-Qualification
? More than 10 sec
? The SRS current measuring can be cause of component malfunction. So the current value is not mentioned in Threshold value to prohibit measuring the current.
? Tolerance band : It is unstable band that ECM detects the failure or not to do.
Test Condition
DBPT circuit resistance(O)
Ignition OFF
1.8 ? < Rs < 3.1 ?