Rain sensor activating wipers absent rain
Thread Starter
|
Registered User
Joined: Feb 2014
Posts: 10
Likes: 0
From: Hotlanta
Rain sensor activating wipers absent rain
Have any of you had your wipers come on automatically on a day when there is no rain whatsoever? A swipe hear, a swipe there, sometimes with two or three at once, not frequent but it does happen despite the fact that it is dry as a bone outside. The only thing that comes to mind is the heavy pollen count but that shouldn't be triggering the wipers.
All Star
Joined: Nov 2013
Posts: 844
Likes: 1
From: Houston, Texas
Trending Topics
Site Moderator-Dodge Tech
Joined: Sep 2010
Posts: 3,724
Likes: 22
From: Nashville, Tennessee
OPERATION
The microprocessor-based Light Rain Sensor Module (LRSM) (also known as the Light Sensor Module/LSM or the Rain Sensor Module/RSM) senses moisture in the wipe pattern on the outside of the windshield glass and sends electronic messages to the Wireless Ignition Node (WIN) (also known as the Wireless Control Module/WCM or Sentry Key REmote Entry Module/SKREEM) on the Local Interface Network (LIN) data bus. The WIN relays messages back and forth between the LRSM and other electronic modules in the vehicle.
Two InfraRed (IR) diodes within the LRSM generate infrared light beams that are aimed by two of the convex optical lenses of the sensor through the windshield glass. Two additional convex optical lenses of the sensor are focused on the infrared light beams reflected back from the windshield glass and allow the two photocells within the sensor to sense changes in the intensity of these infrared light beams. When sufficient moisture accumulates within the wipe pattern on the windshield glass, less of the infrared light is reflected back and the sensor detects a change in the monitored infrared light beam intensity.
The internal programming of the LRSM then sends the appropriate electronic wipe command messages to the WIN over the LIN data bus, and the WIN relays those messages to the Totally Integrated Power Module (TIPM) over the Controller Area Network (CAN) data bus. The TIPM then responds by activating or deactivating the front wiper system. Similarly, in some vehicle applications the photocells within the LRSM are capable of sensing ambient light levels through the windshield glass and providing electronic light level messages to other modules in the vehicle.
The LRSM operates on battery current received through a fused ignition switch output (run/accessory) circuit controlled by the run-accessory relay. The LRSM receives ground at all times through a take out of the body wire harness with an eyelet terminal that is secured by a ground screw to the body sheet metal. Therefore, the LRSM is operational only when the ignition switch is in the ON or ACCESSORY positions.
It is important to note that the default operation of the automatic wiper system is low speed continuous wipe. Therefore, if no message is received by the TIPM from the LRSM for more than about five seconds when the AUTOMATIC wipe mode is selected, the wipers will default to the low speed continuous wipe operation. It is also noteworthy that the WIN must be properly configured for the automatic wipers option for the automatic wipers to function.
The microprocessor-based Light Rain Sensor Module (LRSM) (also known as the Light Sensor Module/LSM or the Rain Sensor Module/RSM) senses moisture in the wipe pattern on the outside of the windshield glass and sends electronic messages to the Wireless Ignition Node (WIN) (also known as the Wireless Control Module/WCM or Sentry Key REmote Entry Module/SKREEM) on the Local Interface Network (LIN) data bus. The WIN relays messages back and forth between the LRSM and other electronic modules in the vehicle.
Two InfraRed (IR) diodes within the LRSM generate infrared light beams that are aimed by two of the convex optical lenses of the sensor through the windshield glass. Two additional convex optical lenses of the sensor are focused on the infrared light beams reflected back from the windshield glass and allow the two photocells within the sensor to sense changes in the intensity of these infrared light beams. When sufficient moisture accumulates within the wipe pattern on the windshield glass, less of the infrared light is reflected back and the sensor detects a change in the monitored infrared light beam intensity.
The internal programming of the LRSM then sends the appropriate electronic wipe command messages to the WIN over the LIN data bus, and the WIN relays those messages to the Totally Integrated Power Module (TIPM) over the Controller Area Network (CAN) data bus. The TIPM then responds by activating or deactivating the front wiper system. Similarly, in some vehicle applications the photocells within the LRSM are capable of sensing ambient light levels through the windshield glass and providing electronic light level messages to other modules in the vehicle.
The Steering Control Module (SCM) sends electronic wiper switch status and sensitivity level messages over the CAN data bus to the TIPM and the WIN based upon the driver-selected settings of the control **** on the control stalk of the multifunction switch. The WIN receives electronic messages from other electronic modules in the vehicle over the CAN data bus, and the WIN relays the messages to the LRSM over the LIN bus.
The higher the selected sensitivity setting the more sensitive the LRSM is to the accumulated moisture on the windshield glass, and the more frequently the LRSM will send wipe commands to the TIPM to operate the front wiper system. The third (middle) sensitivity setting is set up for optimal operation of the automatic wipers under most typical driving conditions.
The higher the selected sensitivity setting the more sensitive the LRSM is to the accumulated moisture on the windshield glass, and the more frequently the LRSM will send wipe commands to the TIPM to operate the front wiper system. The third (middle) sensitivity setting is set up for optimal operation of the automatic wipers under most typical driving conditions.
The LRSM operates on battery current received through a fused ignition switch output (run/accessory) circuit controlled by the run-accessory relay. The LRSM receives ground at all times through a take out of the body wire harness with an eyelet terminal that is secured by a ground screw to the body sheet metal. Therefore, the LRSM is operational only when the ignition switch is in the ON or ACCESSORY positions.
It is important to note that the default operation of the automatic wiper system is low speed continuous wipe. Therefore, if no message is received by the TIPM from the LRSM for more than about five seconds when the AUTOMATIC wipe mode is selected, the wipers will default to the low speed continuous wipe operation. It is also noteworthy that the WIN must be properly configured for the automatic wipers option for the automatic wipers to function.
Rookie
Joined: Feb 2013
Posts: 76
Likes: 0
I had no idea that the MFS had any effect on the auto wipers' sensitivity. I thought that was just a remnant from the Autowiper OFF setting in the DIC and so I just keep it on the lowest intermittent setting. Guess I'll bump it up a few notches.
Thanks, TNTech.
Thanks, TNTech.
Veteran
Joined: Dec 2013
Posts: 373
Likes: 1
From: Michigan
lolYep, if you have the automatic wipers turned off in the Uconnect system (box unchecked), then the MFS operates in the traditional manner (intermittent and variable, low, high).
However, if you have the automatic wipers turned on (box checked), then the MFS switch controls the sensitivity of the system. Default sensitivity is three, but I've found setting two works just fine. It also is a quick way to turn off the auto wipers without having to go to the UConnect system settings to do it.
Truth be told, that is how I found out about it because my auto wipers weren't working. Turns out, it was because the MFS was switched to off. Only then did I discover that it also controlled sensitivity.
