What does it mean?
B2427 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Passenger Solar Radiation Sensor Circuit Short to Ground .
Symptoms
- The climate system behaves as if it is permanently in full sunshine, blowing cold or running a high blower speed
- The passenger side stays cool even with the temperature turned right up
- Blower speed is higher than expected at night or inside a garage
- The sunload reading is stuck at its maximum value regardless of the light
- Cabin temperature is uncomfortable and never settles
Likely causes
- Signal wire pinched against the dash frame or a mounting screw during trim work
- Water from a windscreen or cowl leak sitting in the sensor connector and bridging pins
- Internally shorted sunload sensor
- Dash top loom chafed on a sharp edge under the speaker grille
- Corrosion tracking between the signal and ground pins in the connector
- Damage from an accessory such as a camera wired into the same area of loom
- Faulty climate control module input holding the signal low
How to fix it
- Compare the passenger sunload reading with the driver side sensor in a dark garage, where both should read close to zero
- Unplug the sensor and check whether the reported value moves to the open circuit end of the scale
- If the value does not move, the short is in the harness rather than in the sensor
- Measure resistance from the signal wire to ground with the sensor and the module both disconnected
- Inspect the dash top loom and the area around the windscreen for moisture and chafe damage
- Dry and clean the connector, repair the shorted section and reroute the loom clear of sharp edges
- Replace the sensor if it is internally shorted, then confirm the value tracks light correctly