2023-2026 Ram, Jeep, Dodge Rain Sensor Failure TSB S2308000120

The Manufacturer Communication S2308000120 Rev. F addresses a common problem affecting several 2023-2026 Ram, Jeep, and Dodge models: inoperative rain-sensing auto wipers and automatic headlamps. This issue is typically caused by an internal failure of the rain sensor itself. Owners experiencing a Jeep Compass rain sensor failure or similar issues in other affected models may notice that their automatic wipers do not activate in rain or that their headlamps do not switch on automatically in low light conditions.

This technical service bulletin (TSB) provides technicians with a detailed guide for diagnosing and resolving these issues, often linked to specific Diagnostic Trouble Codes (DTCs). The document emphasizes careful inspection and specific handling procedures for the rain sensor to prevent further malfunctions.

Symptoms of Rain Sensor Failure

Owners may observe one or both of the following symptoms:

• Rain-sensitive wipers are not functioning: The automatic wipers fail to activate or respond correctly to rain on the windshield.
• Automatic headlamps are inoperative: The headlamps do not turn on automatically when light conditions require them.

These symptoms point towards a potential internal failure of the rain sensor, which is a critical component for both systems. If you are experiencing a Jeep Compass rain sensor failure, it's important to have your vehicle inspected.

Diagnostic Trouble Codes (DTCs)

When the rain sensor or related systems malfunction, technicians may find one or more of the following Diagnostic Trouble Codes (DTCs) stored in the vehicle's computer system:

Code	Description
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

These codes specifically indicate various internal faults within the rain sensor module or its components, such as the light or humidity sensors.

Important Warnings for Owners and Technicians

This communication includes critical advisories to ensure proper diagnosis and repair:

• "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." This highlights the delicate nature of the sensor's internal components.
• "NOTE: Before performing any removal or troubleshooting activity, visually inspect the rain sensor installation from both outside and inside the vehicle." A thorough visual check is the first step to identify obvious issues.
• "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." Owners should be aware of these operational limitations when testing the system.
• "Removing power from the light rain sensor by disconnecting the vehicle battery is required for proper sensor calibration." This specific step is crucial for ensuring the sensor recalibrates correctly after service.
• "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 instruction ensures that any faulty components can be properly analyzed by the manufacturer.

Diagnosis and Repair Overview

The repair procedure, detailed in Manufacturer Communication S2308000120 Rev. F, begins with verifying basic settings and conducting a comprehensive visual inspection.

1. Initial Checks: Ensure the auto-on wiper selection is enabled in the radio settings and the headlamp switch is set to AUTO-ON.
2. Windshield Inspection: Inspect the windshield area around the light rain sensor for any obstructions like tint, aftermarket equipment, or cracks. If the windshield was recently replaced, the sensor mounting area should be carefully checked.
3. Visual Sensor Inspection: Technicians must visually inspect the sensor at the glass for air bubbles or damage to the SILGel membrane, which could indicate improper installation or a recent windshield replacement. Photos of the sensor's overall appearance and proper seating must be attached to documentation.
4. Functional Testing:
   • Rain-sensing wipers: Test by splashing water near the sensor with the vehicle in "Park" and ignition on, confirming activation in the cluster or radio.
   • Auto headlamps: Block light to the sensor with an opaque object, ensuring the headlamp switch is in auto mode, and verify proper operation.
5. DTC and Battery Voltage Review: Record any DTCs and associated environmental data, particularly battery voltage. If DTCs are triggered by low battery voltage, the sensor should not be removed; instead, erase the DTCs and retest.
6. Connector Security: Remove the rear-view mirror cover and check the sensor connector. Use the "push-pull-push method" to secure loose connections. If the connector and harness are undamaged, disconnect and reconnect the sensor to ensure proper electrical contact and verify it's fully retained by its bracket.
7. DTC Erasure and Calibration: Erase DTCs and perform a key cycle (key off for 1 minute with wiTECH disconnected). Disconnecting the vehicle battery is essential for proper sensor calibration. After battery reconnection, retest the system. If DTCs persist, perform at least three key cycles to allow the sensor to relearn its calibration, or follow Service Library DTC diagnostics.

Owner Actions and Next Steps

If you own a 2023-2026 Ram, Jeep, or Dodge vehicle and are experiencing issues with your rain-sensing wipers or automatic headlamps, especially if you suspect a Jeep Compass rain sensor failure, it is recommended to:

• Check Basic Settings: Verify that your auto-on wiper and headlamp settings are correctly enabled in your vehicle's infotainment system and on the headlamp switch.
• Inspect Windshield: Look for any obvious obstructions, tint, or cracks on your windshield in the area of the rain sensor.
• Contact Your Dealership: Schedule an appointment with an authorized Ram, Jeep, or Dodge service center. Inform them of the symptoms you are experiencing and mention Manufacturer Communication S2308000120 Rev. F. They have the necessary tools and expertise to diagnose the specific DTCs and perform the outlined repair procedure.

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Source: NHTSA ID: 11028744, Manufacturer Communication S2308000120 Rev. F