U0184 – Lost Communication With Radio

U0184 – Lost Communication With Radio means the vehicle’s control modules—typically the BCM, PCM, or instrument cluster—can no longer communicate with the radio or infotainment head unit over the CAN bus. Modern radios are integrated into vehicle security, warning chimes, backup camera systems, Bluetooth, and even immobilizer functions. When communication is lost, the radio may stop working, screens may go blank, or other features may malfunction. This guide explains what U0184 means, symptoms, causes, how to diagnose the fault, and the most effective repair options.

What Does U0184 Mean?

U0184 is a generic OBD-II network code indicating that the radio or infotainment module is not responding to messages on the CAN bus. Although the radio is often considered a “comfort” feature, modern systems also handle important functions such as warning tones, camera displays, and vehicle settings.

A loss of communication can occur from wiring damage, a failed radio module, corroded connectors, or low system voltage. Depending on the vehicle, U0184 may generate secondary faults in the cluster, HVAC system, or BCM.

Quick Reference

  • OBD-II Family: U-Code (Network Communication)
  • Scope: Generic
  • System: Infotainment / CAN Bus
  • Difficulty Level: Easy to Moderate
  • Estimated Repair Cost: €50–€600+
  • Last Updated: 22 November 2025

Real-World Example / Field Notes

A compact SUV arrived with a blank infotainment screen and no audio output. The BCM and instrument cluster stored U0184. The root cause was a loose ground stud behind the radio that caused intermittent loss of power. Tightening the ground strap restored full functionality instantly.

In another case, a sedan had flickering radio operation and repeated U0184. The issue was water intrusion into the dash wiring from a clogged sunroof drain, corroding the CAN connector behind the head unit. Cleaning the connector and sealing the drain eliminated the issue.

Symptoms of U0184 – Lost Communication With Radio

  • No audio output: Radio, Bluetooth, or warning chimes may stop working.
  • Blank or frozen display: Screen may not turn on or may reboot continuously.
  • No touchscreen functionality: Input not detected.
  • Backup camera not available: Radio cannot display the video signal.
  • Time, temperature, or vehicle settings missing: Cluster may rely on radio data.
  • No communication with radio via scan tool: “Head unit not responding.”
  • Bluetooth pairing failures: Radio system offline.

Common Causes of U0184

Most Common Causes

  • Radio module losing power or ground
  • Corroded connectors behind the infotainment unit
  • CAN bus wiring faults (shorts, opens, water intrusion)
  • Failed or locked-up radio module
  • Low battery voltage or failing alternator

Less Common Causes

  • Aftermarket stereo installations damaging CAN wiring
  • Rodent damage behind dashboard
  • Incorrect wiring during accessory installation (dash cams, trackers)
  • Failed CAN terminating resistor (rare in infotainment circuits)
  • Internal display controller failure

Diagnosis: Step-by-Step Guide

Diagnosing U0184 focuses on confirming radio power, checking CAN signals, and inspecting connectors behind the head unit.

Tools You’ll Need

Advanced scan tool, trim removal tools, multimeter, wiring diagrams, backprobe kit, CAN breakout box, and optional oscilloscope.

  1. Scan all modules: Confirm U0184 is present and check for voltage-related codes.
  2. Check radio power supply: Verify main power, accessory (ACC) power, and ground circuits.
  3. Inspect radio connectors: Remove head unit and check for loose pins or corrosion.
  4. Test CAN-H and CAN-L at the radio: Should read ~3.5V (H) and ~1.5V (L).
  5. Check for water intrusion: Common near windshield, sunroof drains, or HVAC ducts.
  6. Test continuity on CAN lines: Look for opens between radio and BCM.
  7. Wiggle test wiring: Move connectors and harness while checking communication status.
  8. Disconnect aftermarket accessories: They often introduce CAN noise or shorts.
  9. Try rebooting the radio: Some vehicles require a “hard reset” by removing fuses.
  10. Oscilloscope CAN test: Look for distorted or missing differential waveforms.

Pro Tip: A large percentage of U0184 cases come from poor grounds behind the radio. Always check and tighten ground straps before suspecting module failure.

Possible Fixes & Repair Costs

  • Repair or clean radio connectors: €20–€80
  • Repair CAN wiring behind dashboard: €60–€200
  • Fix water intrusion sources: €50–€250
  • Replace radio fuse or repair power feed: €10–€50
  • Replace infotainment/radio module: €200–€600+
  • Charging system repair (if voltage-related): €120–€400

Can I Still Drive With U0184?

Yes, in most cases. U0184 does not typically affect engine or transmission operation. However, features like the backup camera, warning chimes, Bluetooth, or vehicle settings may stop working. If the screen controls climate or safety functions, driving may be less safe or less convenient.

Related Codes

  • U0151 – Instrument Panel Communication Fault
  • U0141 – Steering System Network Communication Fault
  • U0121 – Lost Communication With Anti-Lock Brake System (ABS) Control Module
  • U0102 – Lost Communication With Transfer Case Control Module
  • U0101 – Lost Communication With TCM
  • U0100 – Lost Communication With ECM/PCM "A"
  • U0195 – Lost Communication With Audio AMP
  • U0194 – Lost Communication With Audio Display
  • U0188 – Lost Communication With Video Display
  • U0185 – Lost Communication With TV/Telematics Unit

Key Takeaways

  • U0184 means the radio/infotainment module is not communicating over the CAN bus.
  • Common causes include connector corrosion, wiring faults, and low voltage.
  • Backup camera, audio, and vehicle settings may stop working.
  • Most repairs are inexpensive unless the radio module has failed.

FAQ

Does U0184 mean the radio is dead?

Not always. Many cases are caused by poor grounds, loose connectors, or CAN wiring faults.

Can a weak battery cause U0184?

Yes. Low voltage can cause infotainment modules to shut down or reboot repeatedly.

Will U0184 affect the backup camera?

Yes. Most cameras rely on the radio for display, so a communication dropout can disable the image.

Is it safe to drive with U0184?

Generally yes, unless the radio controls safety or climate settings. Always confirm what functions your head unit controls.

Can aftermarket radios cause U0184?

Very often. Incorrect wiring, missing CAN adapters, or poor integration can cause communication faults.