U0186
Lost Communication With Audio Amplifier A
Communication network
Generic OBD-II
Low
What it means
U0186 means the vehicle's network has stopped receiving expected messages from the audio amplifier. That module powers the speakers in the sound system. You get no sound or distorted/low audio, but nothing about driving is affected.
Low
Can I keep driving? Yes — this only affects audio. The vehicle drives normally; you'll just have no or degraded sound.
Common symptoms
What you'll notice
- Warning light or message related to the affected system
- The audio amplifier's features stop working or work intermittently
- Stored 'lost communication' code in the module that reports the fault
- No sound, or distorted/low audio from the speakers
Common causes
Most likely first
- Power or ground fault feeding the audio amplifierLikely
- Damaged wiring or a loose/corroded connector at the audio amplifierCommon
- Break in the CAN/bus wiring between the module and the rest of the networkCommon
- The audio amplifier itself has failed internallyLess often
- Low battery voltage or a recent battery disconnect knocking modules off the busLess often
How to diagnose & fix
Work through it in order
- Check battery voltage and charge; a weak battery or recent disconnect is a common, easy cause.
- Scan all modules and confirm whether only the audio amplifier is missing or several are — that narrows wiring vs. module.
- Verify power and ground at the audio amplifier's connector.
- Inspect the connector and harness to the audio amplifier for damage, corrosion, or backed-out pins.
- Check for a manufacturer software update or reflash; if wiring and power are good, replace the failed module. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with U0186?+
Yes — this only affects audio. The vehicle drives normally; you'll just have no or degraded sound.
Can I just clear U0186?+
You can clear it, but if the module is still offline the code returns as soon as the network looks for it. Fix the power, wiring, or module first.
Related codes
Often seen with U0186
Read & clear U0186 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX