GM Service Manual Online
For 1990-2009 cars only

Object Number: 239311  Size: SH

Caution: Standard shop practices, particularly eye protection, should be followed during these operations to avoid personal injury.

Notice: If the vehicle has been exposed to extensive water intrusion, such as water leaks, 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 SIR.

GM vehicles are designed to operate under normal environmental conditions. The design criteria for sealing materials and components takes into consideration the sealing forces that are required in order to withstand the natural elements. The specifications do not take into consideration all artificial conditions (such as high pressure car washes).

The water test procedure has been correlated to the natural elements. The watertest determines the ability of a vehicle to perform under normal operating conditions.

Repairing waterleaks requires the following actions:

    • Proper testing
    • Proper diagnosis
    • Adjustment of the misaligned components
    • Application of proven repair materials

First find the conditions under which the leak occurs.

If the general leak area is found, use a localized test (spot test) such as a water hose or air hose in order to isolate the exact entry point. If the leak source is not obvious, use the generalized testing method using the water test equipment. The removal of some interior trim panels or components may be necessary in order to locate and confirm the repairs.


Object Number: 154165  Size: SH

The following specifications are necessary in order to watertest a vehicle:

    • Type of nozzle: A full cone spray with a 60 degrees included angle and a full jet spray nozzle No. ½ GG-25, or the equivalent.
    • Nozzle height: Approximately 166 mm (63 in) from the floor.
    • Volume of flow: 14 liters (3.7 gal) per minute.
    • Pressure: 156 kPa (22 psi) measured at the nozzle.
    • Windshield and front body pillar: Approximately 30 degrees down, 45 degrees towards the rear and aimed at the corner of the windshield.
    • Side: Approximately 30 degrees down, 45 degrees towards the rear and aimed at the center of the rear door or rear quarter.
    • Back window and rear compartment lid: Approximately 30 degrees down, 30 degrees towards the front and aimed approximately 600 mm (24 in) from the corner of the back window.

If you are unable to obtain the specified water pressure of 155 kpa (22 psi) because of local situations, reposition both stands closer to the body until you obtain the water spray overlap.

Important: Do not use a high pressure water or air hose in order to test the repaired areas. The fresh repair material may dislodge under abnormal pressure.

Pinpoint the leak area before making any repair. Random repair may only temporarily restrict water entry. Random repairs may make the following procedures more difficult:

    • Future diagnosis
    • Future repair