Nuisance Reversals

A nuisance reversal describes a condition where the obstacle detection feature (also known as the Excess Force Limitation/EFL feature) reverses sunroof glass or sunshade movement to protect for an obstacle, but no obvious obstacle exists. When the motor speed decreases beyond what the module has learned during previous cycles, it is interpreted by the module as an obstacle having been encountered. However, other conditions such as low ambient temperatures or low system voltage levels can slow sunroof or sunshade operation, which may be misinterpreted by the module as an obstacle resulting in a nuisance reversal.

To test for this condition, first verify that the system voltage of the vehicle is at or above 12.5 volts. Now, carefully observe and listen while the reversal occurs as the sunroof or sunshade is closed and proceed as follows.

• If the nuisance reversals always occur at the same point in the sunroof or sunshade travel, perform the DUAL PANE SUNROOF OR SUNSHADE OBSTACLE DETECTION REVERSAL OVERRIDE procedure. Refer to MOTOR, SUNROOF, STANDARD PROCEDURE . This will force the motor to try to learn the new friction level during the override closing event.
• If the nuisance reversals continue to occur at the same point in the sunroof or sunshade travel following the performance of the override procedure, note the location where the reversal occurs and inspect that area for binding parts. If any noise is noted during the reversal, identify the source of the noise. For example, if the reversal always occurs in the last 7.6 centimeters (3 inches) of sunroof travel, observe the wind deflector for binding as it is pushed downward or examine the guides in that area of travel for debris in the tracks or damage to the cable track. It may be necessary to remove the sliding glass panel, the wind deflector or the drain channel to observe the sunroof mechanism in operation in order to identify the specific source of binding.
• Improper glass adjustment and glass fit to the roof sheet metal and the fixed glass panel can cause nuisance reversals to occur. In those cases, proper adjustment of the two glass panels may resolve the problem. Refer to GLASS, SUNROOF, FRONT, ADJUSTMENTS .
• If the nuisance reversals only occur while driving under rough road conditions, verify there are no localized bind points in the sunroof or sunshade travel. Striking a large enough bump or driving on washboard roads could be expected to cause an occasional nuisance reversal. The software is programmed to detect rough road events and minimize them, but can't completely eliminate them without disabling the obstacle detection feature.
• If the nuisance reversals only occur as the engine is being turned OFF or during the start or stall of another electric motor in the vehicle (power window or power seat motors) then a voltage drop or high current draw event may be reducing the electrical power available to the sunroof or sunshade motor. Check for loose connections or excessive resistance in the battery and ground circuits to the sunroof and sunshade motors. The software is programmed to compensate for voltage drop or high current draw events when proper wiring and connections are functional.
• If the nuisance reversals are intermittent, cannot be tracked to any specific position and are not resolved by performing the override procedure, replacement of the motor and module unit may be necessary. However, if proper motor and module unit replacement does not resolve the problem, the mechanical cause of the binding must be found and repaired to restore proper sunroof or sunshade operation.