Network, generic

U0491 Invalid Data Received From Digital Disc Player/Changer Module D

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0491 belongs to a fourth networked disc player or changer, module D: frames from that drive still arrive, yet the radio or gateway rejects their content. Its lost-contact partner is U0190; drives A to C have U0488, U0489 and U048A. Separate disc drives did exist, for example the media disc player in GM's 2017 Silverado, Sierra, Suburban, Tahoe and Yukon with entertainment package, which bulletin 17-NA-378 replaced when film sound drifted out of sync with the picture. A fourth unit of this kind is practically unknown, and no manufacturer documents U0491 or publicly assigns the letter D. On a car without such a drive the code hints at coding or software rather than hardware. No MIL; at most disc playback is lost.

Likely causes

Vehicle coding or head-unit software expecting a fourth disc drive that is absent or different
Disc drive D hung up or internally faulty
Poor supply, ground or bus link at the drive

Symptoms

  • Discs in that drive cannot be played
  • Code stored without noticeable fault on cars lacking such a drive

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–400
Time0.3–1.5 h

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

Parts involved

disc changer module d

Related codes

U0190U0488U0489U048A

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