B1259 – Solar Radiation Sensor Circuit Open

The ODBII code B1259 indicates that there is an open circuit in the solar radiation sensor, which measures sunlight intensity for functions like automatic climate control.

The severity of ODBII code B1259 is generally considered moderate.

Common Causes For: B1258 Solar Radiation Sensor Circuit Failure

• Faulty solar radiation sensor
• Open circuit in wiring or connectors
• Corroded or damaged connectors
• Short circuit in the wiring harness
• Poor ground connection
• Malfunctioning body control module (BCM)

Common misdiagnosis for B1259 Solar Radiation Sensor Circuit Open

• Faulty solar radiation sensor
• Wiring issues or shorts in the circuit
• Malfunctioning body control module (BCM)
• Incorrectly diagnosed ambient light sensor issues
• Problems with the vehicle’s electrical system or battery
• Software or calibration errors in the vehicle’s computer systems

Common Troubleshooting Steps

The OBD-II code B1259 indicates an issue with the solar radiation sensor circuit, specifically that the circuit is open. This sensor is typically used in vehicles to measure sunlight intensity, which can affect climate control systems and other functions. Here are some common troubleshooting steps to diagnose and resolve the B1259 code:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information about the solar radiation sensor and its circuit.
• Visual Inspection:
• Inspect the wiring and connectors associated with the solar radiation sensor for any signs of damage, corrosion, or loose connections.
• Look for frayed wires, broken connectors, or any other physical damage.
• Test the Sensor:
• If accessible, disconnect the solar radiation sensor and test it with a multimeter to check for continuity. The sensor should have a specific resistance value; consult the service manual for the correct specifications.
• If the sensor is faulty, replace it.
• Check the Circuit:
• Use a multimeter to check for voltage and ground at the sensor connector. Ensure that the circuit is receiving the proper voltage as specified in the service manual.
• If there is no voltage or ground, trace the wiring back to the power source or ground point to identify any breaks or shorts in the circuit.
• Inspect Related Components:
• Check any related components or modules that may affect the solar radiation sensor, such as the body control module (BCM) or climate control module.
• Ensure that these components are functioning correctly and are not causing the issue.
• Clear the Code:
• After performing repairs or replacements, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional mechanic or technician who has experience with automotive electrical systems. By following these steps, you should be able to identify and resolve the issue related to the B1259 code.