Circuit Description
When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.
The belt pretensioner cannot be deployed independantly and should be deployed with other modules regardless of frontal or side impact. DTC B1657 will set with B1651 or B1652.
In case of the belt tensioner deployment, the SDM maintains the warning lamp ON. Deloyed modules and the SDM should be replaced. After replacement the entire system should be checked.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B1657 Deployment Commanded Pretensioner
Conditions for Running the DTC
Ignition voltage is within the normal operating voltage range.
Conditions for Setting the DTC
The history of the belt pretensioner explosion is in the SDM.
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON.
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
|
Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Has the SDM discharged? | -- | Go to Step 3 | -- |
3 | Visually inspect any damage for the air bag wiring. Is the air bag wiring damaged? | -- | Go to Step 5 | Go to Step 4 |
4 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement Is the replacement complete? | -- | Go to Step 6 | -- |
5 | Replace the air bag wiring. Is the replacement complete? | -- | Go to Step 6 | -- |
6 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
