GM Service Manual Online
For 1990-2009 cars only

Waterleak Diagnosis

Caution: When the vehicle interior has been exposed to extensive water intrusion, such as waterleaks, window left open, driving through high water and so forth, the Sensing and Diagnostic Module (SDM) and the SDM connector may need to be replaced. With the ignition OFF, inspect the area under the front seat and the area around the SDM, including the carpet. If any significant soaking or evidence of significant soaking is detected, the water must be removed, water damage repaired and the SDM and the SDM connector MUST be replaced. Before attempting any of these repairs, the SIR system must be disabled. Refer to the Supplemental Inflatable Restraint (SIR) System for instructions on how to disable the SIR system. Failure to disable the SIR system may result in possible air bag deployment, personal injury or otherwise unneeded SIR system repairs.

GM vehicles are designed in order to operate in normal environmental conditions. The design criteria for sealing materials and components is sufficient to withstand natural elements. The specifications do not take into consideration any of the artificial conditions that may be encountered in high pressure car washes.

The watertest procedure correlates to natural elements. The watertest procedure will determine the ability of a vehicle to perform under normal operating conditions.

Repairing waterleaks involves the following actions:

    • Proper testing
    • Proper diagnosis

The following steps are included in waterleak repairs:

    • Adjusting misaligned components
    • Application of approved repair materials

In order to diagnose waterleaks, find the condition in which the waterleaks occur. The following list indicates some examples of waterleak conditions:

    • The leak is noticed only when the vehicle is parked on an incline.
    • Water is in the spare tire compartment.

If the general leak area is found, isolate the exact entry point by using one of the following tests:

    • A water hose test
    • An air hose test

If the leak source is not obvious, use watertest equipment in order to determine the leak source.

Remove the inner trim panels or any components as needed in order to locate and confirm the repairs.