B1855 – Climate Control Air Temperature Internal Sensor Motor Circuit Short To Battery

The ODBII code B1855 indicates a short circuit in the climate control air temperature internal sensor motor circuit, causing it to connect directly to the battery voltage.

The severity of ODBII code B1855 is moderate.

Common Causes For: B1854 Climate Control Air Temperature Internal Sensor Motor Circuit Open

• Shorted wiring or connectors
• Faulty internal temperature sensor
• Malfunctioning climate control module
• Damaged or corroded connectors
• Grounding issues
• Electrical shorts in the motor circuit

Common misdiagnosis for B1855 Climate Control Air Temperature Internal Sensor Motor Circuit Short To Battery

• Faulty climate control module
• Defective internal temperature sensor
• Wiring issues or shorts in the harness
• Malfunctioning blower motor
• Incorrectly calibrated climate control system
• Issues with the HVAC control panel
• Battery or charging system problems

Common Troubleshooting Steps

The OBD-II code B1855 indicates a problem with the climate control air temperature internal sensor motor circuit, specifically a short to battery. Here are some common troubleshooting steps to diagnose and potentially resolve this issue:

• Check the Vehicle’s Battery and Charging System: Ensure the battery is in good condition and fully charged.
• Check the alternator and charging system for proper operation.
• Inspect Wiring and Connectors: Visually inspect the wiring harness and connectors related to the climate control system, especially those connected to the internal temperature sensor and motor.
• Look for signs of damage, corrosion, fraying, or loose connections.
• Repair or replace any damaged wiring or connectors.
• Test the Internal Temperature Sensor: Locate the internal temperature sensor and test its resistance using a multimeter. Compare the readings to the specifications in the vehicle’s service manual.
• If the sensor is out of specification, replace it.
• Check the Motor Circuit: Inspect the motor that controls the air temperature for any signs of damage or malfunction.
• Test the motor for proper operation by applying direct power to it (if safe to do so) to see if it functions correctly.
• Scan for Additional Codes: Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
• Address any other codes found, as they may be contributing to the problem.
• Check for Short Circuits: Use a multimeter to check for continuity in the wiring harness. Look for any shorts to ground or battery voltage.
• If a short is found, trace the wiring to locate the source and repair it.
• Inspect the Climate Control Module: If all other components check out, the issue may lie within the climate control module itself.
• Check for any software updates or recalls related to the climate control system.
• If necessary, consider replacing the climate control module.
• Clear Codes and Test Drive: After performing repairs, clear the trouble codes using an OBD-II scanner.
• Take the vehicle for a test drive to see if the code reappears.
• Consult a Professional: If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model.Additional Tips: – Always refer to the vehicle’s service manual for specific diagnostic procedures and specifications. – Ensure safety precautions are taken when working with electrical components and systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1855 code.