B1844 – Phone Handset Circuit Failure

The ODBII code B1844 indicates a malfunction in the phone handset circuit, typically related to the vehicle’s hands-free or Bluetooth phone system.

The severity of ODBII code B1844 is generally considered moderate.

Common Causes For: B1843 Wiper Front Power Circuit Short To Ground

• Faulty phone handset
• Damaged wiring or connectors
• Short circuit in the phone circuit
• Malfunctioning control module
• Corroded terminals or connectors
• Software issues or glitches
• Poor ground connection

Common misdiagnosis for B1844 Phone Handset Circuit Failure

• Faulty Bluetooth module
• Defective audio control unit
• Wiring harness issues
• Malfunctioning radio or infotainment system
• Software glitches in the vehicle’s electronic systems
• Battery or power supply problems
• Faulty microphone or speaker components

Common Troubleshooting Steps

The OBD-II code B1844 refers to a “Phone Handset Circuit Failure,” which typically indicates an issue with the vehicle’s hands-free phone system or its associated wiring and components. Here are some common troubleshooting steps to diagnose and potentially resolve this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are multiple issues.
• Inspect Wiring and Connectors:
• Visually inspect the wiring harness and connectors associated with the phone system. Look for any signs of damage, corrosion, or loose connections.
• Pay special attention to the connectors at the phone module and any related components.
• Test the Phone Module:
• If accessible, test the phone module for proper operation. This may involve checking for power and ground at the module.
• If the module is faulty, it may need to be replaced.
• Check the Antenna: If the vehicle has a dedicated phone antenna, ensure it is properly connected and functioning. A faulty antenna can lead to communication issues.
• Inspect the Hands-Free Microphone and Speakers:
• Ensure that the microphone and speakers used for the hands-free system are functioning correctly. A malfunctioning microphone can cause communication errors.
• Test the audio quality and ensure that the microphone is not obstructed.
• Verify Software Updates: Check if there are any software updates available for the vehicle’s infotainment system. Sometimes, software glitches can cause communication issues.
• Reset the System: Disconnect the vehicle’s battery for a few minutes to reset the system. Reconnect and see if the code reappears.
• Consult the Vehicle Manual: Refer to the vehicle’s service manual for specific diagnostic procedures related to the phone system. This can provide additional insights into the components involved.
• Professional Diagnosis: If the issue persists after performing the above steps, consider taking the vehicle to a qualified technician or dealership. They may have specialized diagnostic tools and experience with the specific make and model of your vehicle.
• Check for Environmental Factors: Sometimes, external factors such as interference from other electronic devices can affect the phone system. Ensure that there are no external devices causing interference. By following these steps, you should be able to identify and potentially resolve the issue related to the B1844 code. If you’re not comfortable performing these checks yourself, it’s always best to consult with a professional mechanic.