Case Number: S2308000120 Rev. D
Release Date:

May 2025

Symptom/Vehicle Issue: Rain Sensing Auto Wipers and Auto on Head Lamps Inoperative
Owner Complaint/Technician Observation: The owner complains that the rain-sensitive
wipers and/or the automatic headlamps are not functioning. The technician observed one or more of
the following Diagnostic Trouble Codes (DTCs) have set dependent on the vehicle.
B221D-00 Rain Sensor Module (RSM) Internal
B221D-49 - Rain Sensor Module (RSM) Internal Electronic Failure
B23AA-01 - Implausible Data Received from Rain Sensor - General Electrical Failure
B225F-49 - Light sensor Internal
B11FA-49 - Humidity Sensor Internal

Repair Procedure: Verify that the auto-on wiper selection within the radio settings is set to on and
verify the customer-selected headlamp switch position is positioned for AUTO-ON headlamps.
Inspect the windshield area where the light rain sensor is located, make sure nothing is blocking the
sensor like windshield tint or any other aftermarket equipment, make sure there are no cracks in the
windshield and if a replacement glass, inspect the area of the sensor mounting location.
CAUTION: During installation or removal process of the sensor, the SILGel membrane and
Humidity Flex PCB must not be handled/touched, as this may cause sensor malfunctions
see steps 1-5.
1. Visually inspect the sensor at the glass, looking for air bubbles from a sensor area that is
properly wetted to the glass surface. If there are air bubbles or any other damage to the
SILGel membrane check if the windshield was replaced recently or the sensor was
removed and re-installed recently. This issue might have been caused by not being careful
enough when removing and re-installing the sensor.
2. Functionally check the rain sensing wipers by splashing some water near the area where
the sensor is located. Ensure the vehicle is in “Park” ´position and the ignition is on to test
This document does not authorize warranty repairs. This communication documents a record of past experiences. STAR Online
does not provide any conclusions about what is wrong with the vehicle. Rather, it captures all previous cases known that appear
to be similar or related to the vehicle symptom / condition. You are the expert, and you are responsible for deciding on the
appropriate course of action.

Contact STAR Center, or your Technical Assistance Center Via TechCONNECT or eCONTACT ticket if no
solution is found
FCA US LLC

Version 4.3 10/29/2020

wipers activation. Confirm that the rain-sensitive wipers feature is activated on the cluster
screen or radio (if applicable). Note: The wipers will not operate in the high-speed mode if
the vehicle is in “Park” or travelling below 4 MPH (7 km/h). A car wash is not a reliable test
method due to the limitations mentioned above. For the auto headlamps functional check,
block the light going into the sensor from exterior glass using an opaque object. Ensure the
headlamp switch is in auto mode and verify proper operation.
3. Record DTCs and environmental data by checking the battery voltage recorded when the
DTC is set. If the DTC is triggered due to low battery voltage, do not remove the sensor.
Instead, erase the DTC and repeat the process.
4. Remove the rear-view mirror cover (inside) and make sure the connector to the sensor is
secure, use the push-pull-push method to secure a loose connection. If secure, disconnect
the connector and check for bent or pushed-out terminals and repair if needed. Verify the
light-rain sensor and harness are secure. Verify that the sensor is fully retained by the
bracket, ensuring the two steel retaining clips on the sensor are fully secured to the housing
bracket.
5. Erase the DTCs and perform a key cycle, the key cycle should be key off for 1 minute with
wiTECH disconnected. Removing power from the light rain sensor is required for proper
sensor calibration. Perform a battery disconnect of the light rain sensor by disconnecting
the fuse (fuse number/location dependent upon vehicle) to allow recalibration of the sensor.
Make sure all doors/hood and gate are closed, then turn the ignition back on and test the
operation following step 2 checking for proper operation. If no DTCs return release the
vehicle. If DTCs return, perform a battery disconnect and at least 3 key cycles to make the
sensor relearns the calibration. If DTCs return, follow Service Library DTC diagnostics as
needed.

NOTE: Removed parts must be protected using the plastic cover from the new part, and tape
should be applied to prevent the removed part from being further damaged during shipping.
This ensures that root cause analysis can be performed by Engineering and the supplier.

This document does not authorize warranty repairs. This communication documents a record of past experiences. STAR Online
does not provide any conclusions about what is wrong with the vehicle. Rather, it captures all previous cases known that appear
to be similar or related to the vehicle symptom / condition. You are the expert, and you are responsible for deciding on the
appropriate course of action.

Contact STAR Center, or your Technical Assistance Center Via TechCONNECT or eCONTACT ticket if no
solution is found
FCA US LLC

Version 4.3 10/29/2020