2023-2026 Jeep/Ram/Dodge Rain Sensor Failure TSB

Owners of 2023-2026 Jeep, Ram, and Dodge vehicles may experience issues with their rain-sensing auto wipers and auto-on headlamps becoming inoperative. This problem is often linked to an internal failure of the rain sensor. Manufacturer Communication S2308000120 Rev. E, released in January 2026, provides detailed diagnostic and repair procedures for technicians to address this specific Jeep Ram Dodge rain sensor failure. This bulletin helps resolve the underlying cause, ensuring proper function of these convenience and safety features.

Symptoms

Vehicle owners typically notice that their rain-sensitive wipers do not activate automatically when it rains, or that their automatic headlamps fail to turn on in low-light conditions. These symptoms indicate a potential Jeep Ram Dodge rain sensor failure.

Fault Codes / DTCs

Technicians investigating this issue may find one or more of the following Diagnostic Trouble Codes (DTCs) stored in the vehicle's system, depending on the specific model and failure:

Diagnosis / Trigger Conditions

Diagnosis begins with verifying basic settings: ensure the auto-on wiper selection is enabled in the radio settings and the headlamp switch is set to the auto-on position. A thorough visual inspection of the windshield area where the light rain sensor is located is crucial. Technicians should check for any obstructions like windshield tint or aftermarket equipment, cracks in the glass, or issues with the sensor's mounting if the windshield was recently replaced. Functional checks involve splashing water on the windshield to test wipers (while the vehicle is in "Park" and below 4 MPH) and blocking light to the sensor to test headlamps. It's also important to record DTCs and environmental data, especially battery voltage, as low voltage can trigger false DTCs.

Repair Procedure Summary

The repair procedure outlined in TSB S2308000120 Rev. E focuses on careful inspection and recalibration of the rain sensor.

1. Visual Inspection: Technicians must visually inspect the sensor at the glass for air bubbles or damage to the SILGel membrane. This is particularly important if the windshield was recently replaced or the sensor was re-installed. Photos of the sensor's appearance, both from outside and inside, are required to be attached to documentation.
2. Functional Testing: Perform functional checks of the rain-sensing wipers and auto headlamps as described in the diagnosis section.
3. DTC Analysis: Record any present DTCs and associated environmental data. If low battery voltage is identified as the cause, the sensor should not be removed; instead, erase the DTCs and retest.
4. Connector and Retention Check: Remove the rearview mirror cover and inspect the rain sensor connector for security. If the connector and harness are undamaged, disconnect the sensor for 5 to 10 seconds, then reconnect it to ensure proper electrical contact. Verify that the sensor is fully secured by its bracket and retaining clips.
5. DTC Erase and Calibration: Erase all DTCs and perform a key cycle (key off for 1 minute with wiTECH disconnected). To ensure proper sensor calibration, the vehicle battery must be disconnected to remove power from the light rain sensor. After reconnecting the battery, close all doors and the hood, turn the ignition on, and retest the system. If DTCs reappear, perform at least three key cycles to allow the sensor to relearn its calibration. If issues persist, further diagnostics using the Service Library are recommended.

Important Warnings

• Handling Precautions: During installation or removal, the "SILGel membrane and Humidity Flex PCB must not be handled/touched, as this may cause sensor malfunctions."
• Removed Parts Protection: "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 is to facilitate root cause analysis by Engineering and the supplier.
• Warranty and Conclusions: This document "does not authorize warranty repairs" and "does not provide any conclusions about what is wrong with the vehicle." It serves as a record of past experiences, and technicians are responsible for determining the appropriate course of action.

Source: NHTSA Manufacturer Communication S2308000120 Rev. E