U0231
Lost Communication with Rain Sensor Module
The wiper controller has lost the rain/light sensor module. Automatic wiping and automatic headlight switching stop working; the driver has to operate them manually.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: easy
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
Ordered by how often each turns out to be the cause.
- Rain sensor failedCommon
- LIN wire to sensor openPossible
- Gateway module routing CAN messages incorrectlyLess likely
Parts involved
- Rain Light Sensor
- LIN Wiring
U0231 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.