B1874 – Cellular Phone Handset Not Present

The ODBII code B1874 indicates that the vehicle’s system is detecting that a cellular phone handset is not present or connected, which may affect features related to hands-free calling or Bluetooth functionality.

The severity of ODBII code B1874 is typically considered moderate.

Common Causes For: B1873 Turn Signal / Hazard Power Feed Circuit Short To Ground

• Disconnected or faulty cellular phone module
• Damaged wiring or connectors
• Software or firmware issues
• Faulty vehicle communication network
• Incompatible or unsupported phone model
• Low battery or power issues in the phone
• Bluetooth connectivity problems
• Incorrect vehicle settings or configurations

Common misdiagnosis for B1874 Cellular Phone Handset Not Present

• Faulty Bluetooth module
• Defective audio control module
• Wiring issues or shorts in the harness
• Malfunctioning infotainment system
• Incorrectly configured settings in the vehicle’s system
• Faulty or missing phone integration software
• Issues with the vehicle’s battery or power supply
• Problems with the vehicle’s body control module (BCM)

Common Troubleshooting Steps

The OBD-II code B1874 indicates that the vehicle’s system has detected a problem related to the cellular phone handset not being present or not communicating properly with the vehicle’s onboard systems. This code is often associated with vehicles that have integrated Bluetooth or hands-free phone systems. Here are some common troubleshooting steps to address this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes. Sometimes, multiple codes can provide more context for the issue.
• Inspect the Phone Connection: Ensure that your cellular phone is properly paired with the vehicle’s Bluetooth system. If the phone is not connected, try to reconnect it.
• Reset the Bluetooth System: Turn off the vehicle and restart it. This can sometimes reset the Bluetooth system and clear temporary glitches.
• Check Phone Compatibility: Verify that your phone is compatible with the vehicle’s Bluetooth system. Consult the vehicle’s owner manual or the manufacturer’s website for a list of compatible devices.
• Update Phone Software: Ensure that your phone’s operating system and Bluetooth software are up to date. Sometimes, software updates can resolve connectivity issues.
• Clear Bluetooth Pairings: If the phone is still not recognized, try deleting the existing Bluetooth pairing from both the phone and the vehicle, then re-pair them.
• Inspect Wiring and Connectors: Check the wiring and connectors related to the Bluetooth module in the vehicle. Look for any signs of damage, corrosion, or loose connections.
• Check the Bluetooth Module: If the problem persists, the Bluetooth module itself may be faulty. Testing or replacing the module may be necessary.
• Consult the Owner’s Manual: Refer to the vehicle’s owner’s manual for specific troubleshooting steps related to the Bluetooth system.
• Professional Diagnosis: If you are unable to resolve the issue, consider taking the vehicle to a qualified technician or dealership for a more thorough diagnosis. 1
• Clear the Code: After performing the necessary checks and repairs, clear the trouble code using an OBD-II scanner and see if it returns. By following these steps, you should be able to identify and potentially resolve the issue related to the B1874 code.