Component Tests and General Diagnostics
DIAGNOSIS AND TESTING - SUNROOF SYSTEM
SINGLE PANE SUNROOF
The hard wired circuits between components related to the operation of the single pane power sunroof system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic module integral to the power sunroof motor. If the power sunroof switches, motors and circuitry test okay, but the express or Excess Force Limitation (EFL) features are still ineffective following the calibration and initialization procedures, the motor and module unit must be replaced.
NOTE: If there is no sliding sunroof panel movement when the power sunroof switch OPEN or CLOSE push button is depressed, but there is movement when the VENT push button is depressed, the sunroof module requires calibration. Complete the Single Pane Sunroof Motor And Module Initialization procedure prior to performing any further sunroof diagnosis. Programming and Relearning .
DUAL PANE SUNROOF AND SUNSHADE
The hard wired circuits between components related to the operation of the dual pane power sunroof and sunshade system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic module integral to the power sunroof or power sunshade motor. If the power sunroof or power sunshade switches, motors and circuitry test okay, but the express or Excess Force Limitation (EFL) features are still ineffective following the initialization procedures, the motor and module unit must be replaced.
TEST PREPARATION
- Check Electrical System Voltage - There should be at least 12.5 volts when measured at the battery terminals.
- Ignition Switch Position - The ignition switch should be in the ON or ACCESSORY positions with the engine not running.
- Note Power Sunroof Responses - Depress each of the sunroof switch push buttons one at a time and note the system responses. Try both express (short press duration) and manual (long press duration) for each push button.
- Note Power Sunshade Responses - Depress each of the sunshade switch push buttons one at a time and note the system responses. Try both express (short press duration) and manual (long press duration) for each push button.
Match the noted system responses to the conditions listed in the diagnostic table to determine the possible causes and corrections for the condition.
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. Programming and Relearning. 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. 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.
MOTOR COMMUNICATIONS CHECK
Sunroof and sunshade operation must be synchronized. The two motor and module units share a communication circuit. This communication circuit is not connected to any other communications circuits in the vehicle. When the sunroof and sunshade communications is active and functioning properly, the express (also known as one-touch) mode of operation for both units is enabled. When the motor and module units cannot communicate, express mode is disabled for both units and only the manual mode of operation is enabled.
To test for proper motor communications, first verify that the system voltage of the vehicle is at or above 12.5 volts. Turn the ignition switch to the ON or ACCESSORY position and try to operate the sunroof and sunshade with their respective switches, carefully noting the results. Proceed as follows.
- Both the sunroof and the sunshade operate only in manual mode. Check the communications circuit between the two motor and module units for a short or open circuit. Refer to the appropriate wiring information. Repair the communications circuit if required. If the communications circuit checks okay, one or both motor and module units may have an internal communications failure and may need to be replaced.
- The sunroof moves in manual mode, but the sunshade does not move. Check the ground, fused B(+), fused ignition (run - acc) and switch circuits at the sunshade motor. If the circuits check okay, replace the ineffective sunshade motor and module unit.
- The sunshade moves in manual mode, but the sunroof does not move. Check the ground, fused B(+), fused ignition (run - acc) and switch circuits at the sunroof motor. If the circuits check okay, replace the ineffective sunroof motor and module unit.