Plenum Water Flow Direction and Cleaning
A large percentage of water will flow off the windshield area into the plenum chamber drain system and then down the outside on the plenum to the underside of the vehicle. To ensure that the plenum chamber water management system performs properly, the air inlet grille panel, plenum chamber, and drains must not be blocked with debris.
In the graphic below the gray arrows show the water flow direction in the plenum chamber and drains system.

Plenum Chamber and Drain Valve-Cleaning
The plenum chamber is located in front of the windshield and below the air inlet grille panel.
Rear Compartment Lid Emblem/Nameplate Replacement (VCDi AT)Installation Procedure
Create 8 x 14 mm (5/16 x 15/16 in) slots for MIG-Brazing along the edges
of the drivetrain and front suspension frame front support
as noted from the original panel.
Clean and prepare the attaching surfaces for brazing.
Position the drivetrain and front suspension frame ...
Removal Procedure
Warning: Refer to Approved Equipment for Collision Repair Warning in the
Preface section.
Warning: Refer to Collision Sectioning Warning in the Preface section.
Warning: Refer to Glass and Sheet Metal Handling Warning in the Preface section.
Disable the SIR System. Refer to SIR Dis ...
High Strength Low Alloy Steel
This information provides repair recommendations and general guidelines for
steel classified as High Strength Low Alloy Steel, also known
as HSLA. This type of steel normally has a tensile strength range from 300-700
MPa.
General Motors recommends the following when repairing or replacing th ...