False Wipes (Automatic Wiper Only)

False wipes are unnecessary wipes that occur when the control knob of the right multi-function switch is in one of the five automatic wiper sensitivity positions and no rain or moisture is apparent within the wipe pattern on the windshield glass. Because this system is designed to operate whenever it detects moisture, if the switch is in one of the automatic wiper sensitivity positions any road spray, bug splatters, or mist from passing cars or trucks may occasionally cause the wipers to cycle. These are normal characteristics of this system and are not false wipes.

False wipes generally are the result of foreign material or flaws that interfere with the system optics. The optics for this system allow the Rain Sensor Module (RSM) (also known as the Rain Light Sensor Module/RLSM) to precisely transmit several Infrared (IR) light beams and precisely monitor the intensity of these beams on the outer surface of the windshield glass to determine the presence of moisture. The sensitivity of this system is such that anything that distorts the focus or intensity of the IR light beams or affects the ability of the photo diodes within the RSM to see and accurately measure these light beams can result in the RSM logic misinterpreting the resulting input data as moisture on the windshield. The optics for this system include the lenses of the RSM, the lenses of the RSM bracket, the adhesive pad layer that bonds the RSM bracket to the inside of the windshield, and the windshield glass.

The following procedure should only be used if false wipe occurrences are frequent and persistent. Perform diagnosis of the front wiper system, the right multi-function switch, the Steering Control Module (SCM) and the RSM using a diagnostic scan tool and the appropriate diagnostic procedures before performing the following:

1. Carefully inspect the outer surface of the windshield glass for physical damage, including scratches, cracks or chips in the vicinity of the RSM mounting bracket lenses. Scratches, cracks or chips in the windshield glass outside the area of the RSM mounting bracket lenses will not cause false wipes.  If OK, go to step  2. If not OK, replace the damaged windshield.
2. From the outside of the windshield glass, carefully inspect the adhesive layer between the windshield glass and the RSM bracket for any large voids. If an adhesive void greater than about 1 millimeter (0.04 inch) is observed, replace the flawed RSM mounting bracket and windshield unit. If OK, go to step  3.
3. Lightly pull the RSM away from the windshield bracket to confirm that both module sliding cam locks are fully engaged with all four pins of the mounting bracket on the inside of the windshield glass. If OK, go to step  4. If not OK, reinstall the module onto the bracket as required.
4. Remove the RSM from the mounting bracket. Inspect the RSM lenses and the mounting bracket lenses for contamination. If OK, go to step  5. If not OK, clean any foreign material from each of these lenses using rubbing alcohol and a lint-free cloth.
5. Carefully inspect the RSM for any physical damage, including scratches on the RSM lenses. If OK, go to step  6. If not OK, replace the damaged RSM.
6. Carefully inspect the RSM mounting bracket for any physical damage, including scratches on the RSM bracket lenses. If not OK, replace the damaged RSM bracket and windshield as a unit.