Code Definition

B221D — Rain Sensor Module Internal Fault

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Jeep

About B221D

B221D is a generic (obd-ii standard) body diagnostic trouble code recorded for Jeep vehicles. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B221D is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B221D is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Body Control Module (BCM) communicates with the Rain Sensor Module (RSM) over a LIN or dedicated serial link to manage automatic wiper operation based on moisture detected on the windscreen. DTC B221D is set when the BCM or the RSM detects an internal fault within the rain sensor module itself, such as a processor error, internal voltage rail fault, or a failed self diagnostic check at module wake. This fault is typically logged when the ignition is on and the module is powered but is unable to operate or communicate correctly with the BCM. When this code is set the automatic wiper feature...

Join TaT to view the complete code information and diagnostic details.

Quick Facts