Case Number: S2308000120 Rev. F
Release Date:

January 2026

Symptom/Vehicle Issue: Rain Sensing Auto Wipers and Auto on Head Lamps
Inoperative. Rain Sensor Internal Failure.
Models Affected:
2023-2026 Ram 1500 (DT), 2500 (DJ), 3500 (D2 and DD), 4500/5500 (DP)
2024-2026 Jeep Wagoneer S (KM)
2024-2026 Dodge Charger (LB)
2023-2026 Jeep Compass (MP)
2023-2026 Dodge Durango (WD)
2023-2026 Jeep Grand Cherokee (WL)
2023-2026 Jeep Wagoneer (WS)
2023-2026 Ram Promaster (VF)
Owner Complaint/Technician Observation: The owner complains that the rainsensitive 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-00 - Implausible Data Received from Rain Sensor - General
Electrical Failure
B225F-49 - Light sensor Internal
B11FA-49 - Humidity Sensor Internal
B2131-09 - Humidity Light Rain Light Sensor Component Failures

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

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.

<<<NOTE>>> Before performing any removal or troubleshooting activity, visually
inspect the rain sensor installation from both outside and inside the vehicle.

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

From the outside, take clear photos showing the overall appearance of the sensor,
ensuring there are no visible air bubbles or detachment between the SilGel
membrane and the windshield.
From the inside, take photos verifying that the sensor is properly seated and fully
secured to the windshield bracket.
Attach all photos to the submitted documentation/claim before proceeding with any
further steps
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 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 the connector and harness appear undamaged, disconnect the
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

rain sensor, wait for 5 to 10 seconds, and reconnect it to verify proper
electrical contact. Then 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
by disconnecting the vehicle battery is required for proper sensor calibration.
After performing the battery disconnect, close all doors and hood, turn the
ignition back on, and retest operation following step 2. If no DTCs return,
release the vehicle. If DTCs reappear, perform at least three key cycles to
allow the sensor to relearn its calibration. If issues persist, follow the 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