What Does B1258 Mean?
This code indicates the Body Control Module (BCM) has detected an electrical fault in the solar radiation sensor circuit. The solar radiation sensor monitors sunlight intensity to help the automatic climate control system adjust cabin temperature and airflow distribution. The BCM has identified an open circuit, short circuit, or signal voltage that is outside the expected range from this sensor.
Common Causes
45%
Failed or damaged solar radiation sensor due to internal component failure or physical damage to sensor housing
30%
Wiring harness damage, corrosion, or broken wires between sensor and BCM, often from water intrusion at dashboard area
15%
Corroded or loose connector at sensor or BCM causing intermittent or poor electrical contact
10%
BCM internal circuit failure affecting solar sensor input channel
Diagnostic Steps
1
Step 1: Visually inspect the solar radiation sensor (typically located on top of dashboard near windshield). Check for physical damage, cracks in sensor housing, debris blocking sensor, or obvious wiring damage. Remove sensor if needed to inspect underside and connector.
2
Step 2: Using a digital multimeter, check sensor connector for proper voltage supply (typically 5V reference) and ground at the sensor harness side with ignition on. Verify continuity of all wires from sensor connector back to BCM connector per wiring diagram.
3
Step 3: Test the solar radiation sensor by measuring resistance or voltage output across sensor terminals while varying light exposure with a bright flashlight. Compare readings to manufacturer specifications (sensor should show changing resistance/voltage with light intensity changes).
4
Step 4: If sensor tests good and wiring is intact, inspect BCM connectors for corrosion, bent pins, or water damage. Check for technical service bulletins regarding BCM software updates that may address false solar sensor codes.
5
Step 5: After repair, clear codes, operate climate control system through all modes including AUTO mode, and verify sensor signal is being received properly by monitoring live data for solar radiation sensor voltage/intensity readings.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an electrical fault in the solar radiation sensor circuit. The solar radiation sensor monitors sunlight intensity to help the automatic climate control system adjust cabin temperature and airflow distribution. The BCM has identified an o...
The most common cause of B1258 (Solar Radiation Sensor Circuit Failure) is: Failed or damaged solar radiation sensor due to internal component failure or physical damage to sensor housing
Typical repair costs for B1258 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle safety or drivability. The automatic climate control system may not adjust optimally for sunlight conditions, requiring manual adjustment of temperature and fan speed. Repair at convenience.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1258 to identify the root cause.
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Quick Info
Category
Body
System
Climate Control System
Difficulty
Type
Manufacturer
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