Network, generic

U0186 Lost Communication With Audio Amplifier A

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0186 means the external audio amplifier A has dropped off the bus; the radio or cluster store it, and the speakers usually go quiet. GM PIC6153 (Volt 2016 with premium audio) warns against replacing the amplifier and asks to inspect its X1 connector, especially pin 4 (B+) and pin 8 (ground). Chrysler bulletin 08-020-14 (Ram, Durango, Grand Cherokee 2013-2014) flashes the amplifier when it shows as absent in the wiTECH network view, after a power cycle via fuse F71. Mazda SA-070-22 (Mazda3, CX-30) traces U0186:08 to a backed-out MOST pin at the connectivity master unit, reproducible by tapping the dash. GM's Saab list calls it the speaker amplifier. Sound lost or crackling; no MIL. U0262 is amplifier B.

Likely causes

Spread or backed-out terminals at amplifier or head unit connector (GM, Mazda)
Amplifier software stops bus communication, fixed by flash (Chrysler)
Amplifier fuse blown or ground loose
Audio amplifier A faulty

Symptoms

  • No sound or radio muted
  • Crackling or intermittent audio
  • Chimes or warning tones missing

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–900
Time0.3–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

audio amplifier acan bus wiring

Related codes

U0487U0262U0184

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, saabwisonline.com.