U0449Invalid Data Received From Serial Data Gateway Module C
- Generic OBD-II code · Network
- How the car detects it
- U0449 points at serial data gateway module C; its lost-contact partner is U0148. The receiver logs it when C keeps transmitting, yet the content breaks the rules agreed for that message, for instance a wrong length, a frozen counter or a bad checksum. No manufacturer documents U0449 publicly. How strictly receivers police gateway traffic is visible at GM: in one 2024 table the ECM checks the data length code of several frames that the gateway forwards from two CAN buses, and a wrong length lasting 10 s sets the gateway A code as a two-trip fault, while a missing frame sets a separate maker-specific code. A third gateway mostly appears in vehicles with many separate networks. Symptoms depend on which networks C joins; several unrelated warnings at once are typical.
- What you may notice
- Several unrelated warnings in the cluster
- Functions on one network segment unavailable
- Likely causes
- PossibleGateway C software sends frames in a layout the receiver does not expect
- PossibleWiring, termination or connector fault on a network served by gateway C
- RareLow voltage or poor ground at gateway C
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.