Network, generic

U0447 Invalid Data Received From Serial Data Gateway Module A

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

As the central gateway, serial data gateway module A links the vehicle networks and forwards messages between them. U0447 means a receiver gets gateway frames with failed protection; for lost contact the code is U0146. In GM's 2025 tables, many receiving modules run this test: the ECM checks rolling count, protection value and checksum of backup power mode signals, a Type B code (two trips) follows after 3 bad samples out of 10, the TCM uses Type A; camera and radar modules allow 0.625 s, stay non-MIL and drop adaptive cruise. GM bulletin 23-NA-206 lists U0447 among history codes to ignore. Audi bulletin 2069299 for 2022-24 Q4 e-tron finds U044700 in both brake modules while the engine module reports U014600, and replaces gateway J533. VW reports it in the ECM of 2013-19 Golf models.

Likely causes

Gateway hardware or software fault, update or replacement of the gateway
Receiver software logs the code without a real fault (history entry)
Low battery voltage or poor ground at the gateway during wake-up or power mode changes

Symptoms

  • Several warning messages in the instrument cluster at once
  • Adaptive cruise or camera-based assistance unavailable
  • Check engine light on in vehicles that rate the fault as MIL-relevant

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–900
Time0.3–2.5 h

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

Parts involved

vehicle gatewaycan bus wiring

Related codes

U0146U0448U0422

References: gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.