
Warning: If the vehicle interior is exposed to moisture and becomes soaked up to the level of the sensing and diagnostic module (SDM), the SDM and SDM harness connector must be replaced. The SDM could be activated when powered, which could cause airbag deployment and result in personal injury.
Depending on the location of the waterleak, you may have to remove certain interior components in order to repair the leak.

Air Hose Test
Stationary Window Waterleak RepairRemoval Procedure
Warning: Refer to Approved Equipment for Collision Repair 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
Disabling and Enabling.
Disconnect the negative battery cable. Refer to ...
Instrument Panel Compartment Replacement
Preliminary Procedure
Remove the instrument panel outer trim cover - right side. Refer to
Instrument Panel Outer Trim Cover Replacement - Right Side.
Instrument Panel Compartment Screw (Qty: 5)
Caution: Refer to Fastener Caution in the Preface section.
Tighten
2.5 N·m (22 lb in)
...
Test Probe Caution
Caution: Do not insert test equipment probes (DMM etc.) into any
connector or fuse block terminal. The diameter of the test probes will
deform most terminals. A deformed terminal will cause a poor connection, which
will result in a system failure. Always use the EL-35616
GM-Approved Terminal T ...