This information provides repair recommendations and general guidelines for steel classified as Ultra High Strength Dual Phase Steel (Dual Phase Steel with a tensile strength greater than 800 MPa), also known as DPX.
General Motors recommends the following when repairing or replacing this type of steel during collision repair.
Note:
Recommended Repairs:
Special Tools and Equipment

Mild Steel
Frame and UnderbodyInstallation Procedure
Drill 8 mm (5/16 in) for plug welding along the edges of the rear inner
wheelhouse as noted from the original panel.
Note: If the location of the original plug weld holes can not be
determined, space the plug weld holes every 40 mm (1½ in).
Clean and prepare the attaching & ...
Deployment Outside Vehicle for Seat Belt Pretensioners
Deploy the seat belt pretensioners outside of the vehicle when the vehicle
will be returned to service. Situations that require deployment
outside of the vehicle include the following:
Using the SIR diagnostics, you determine that the seat belt pretensioner
is malfunctioning.
The pretens ...
Installation Procedure
Drill 8 mm (5/16 in) for plug welding along the edges of the service
panel as noted from the original panel.
Clean and prepare the attaching surfaces for welding.
Apply one-part windshield urethane adhesive as noted
from the original panel.
Position the roof ...