Network, generic

U02A8 Lost Communication With Engine Sound Control 2

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

A second engine sound control exists where one unit is not enough, for example when interior speakers and an exterior sound source are handled separately or two actuators sit at different points of the body. Active sound design covers both directions: inside it shapes what occupants hear, outside it can give a car a recognisable voice. U02A8 is stored when unit 2 drops off the network while unit 1 may still work. Keep it apart from pedestrian warning sound, which on electric cars has its own legal basis and module. No manufacturer documents U02A8 publicly; Ford, for one, runs its engine sound enhancement inside the audio control module, enabled by software. The fault does not affect driving, emissions or engine control, only the sound picture.

Likely causes

Fuse, supply or ground of sound unit 2 faulty

Water or corrosion at a connector in an exposed mounting point

Unit 2 coded as fitted but missing or disabled

Sound control unit 2 internally failed

Symptoms

Part of the engine sound effect missing
Code stored without other noticeable effect

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€0–800

Time0.3–2 h

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

Parts involved

engine sound module 2vehicle bus wiring

Related codes

U02A7

References: en.wikipedia.org, static.nhtsa.gov, en.wikipedia.org.