Fault code lookup

NetworkU0044

Serious

Severity: Serious - have it checked soon

Vehicle Communication Bus B (-) High

22 brands affected · Generic SAE J2012 description.

Key terms: Control module: a small computer that runs one part of the car · SAE J2012: the standard generic code list

1What it means in plain English

Control modules in the car cannot communicate with each other over the vehicle network.

2Common causes

  1. Wiring or connector fault on the communication bus
  2. Faulty control module
  3. Low battery voltage or poor ground
  4. Water ingress in a connector or module
  5. Aftermarket device interfering with the bus

3Can I drive?

Serious · drive with care

The car may run normally or may not run at all. If the module that has lost communication controls steering, brakes, park brake, charging or engine cooling, drive only if those systems feel normal; stop safely if the steering becomes heavy, a brake warning appears, or the engine temperature climbs. If the car will not start or runs badly, have it towed.

This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.

4Brand data 22

BrandCodeDescriptionSystem
Ashok Leyland CVU0044Image Processing. (Sensor B.) - Loss Or Error In Messages BrandNetwork
BAIC MotorU0044Vehicle Communication Bus B High BrandNetwork
BYDU0044Vehicle Communication Bus B High BrandNetwork
CheryU0044Vehicle Communication Bus B High BrandNetwork
DaewooU0044Vehicle Communication Bus B High BrandNetwork
DFFSU0044Vehicle Communication Bus B High BrandNetwork
DFFXU0044Vehicle Communication Bus B High BrandNetwork
DFXKU0044Vehicle Communication Bus B High BrandNetwork
EOBDU0044Sõiduki sidebuss B (-) kõrge BrandNetwork
GeelyU0044Vehicle Communication Bus B High BrandNetwork
GMU0044Vehicle Communication Bus B (-) High BrandNetwork
Great WallU0044Vehicle Communication Bus B High BrandNetwork
HafeiU0044Vehicle Communication Bus B High BrandNetwork
HondaU0044Vehicle Communication Bus B (-) High SAENetwork
HyundaiU0044Vehicle Communication Bus B (-) High SAENetwork
Land RoverU0044Vehicle communication bus B(-) high BrandNetwork
PeugeotU0044Vehicle Communication Bus B (-) High SAENetwork
ProtonU0044Vehicle Communication Bus B (-) High SAENetwork
SaabU0044Vehicle Communication Bus B (-) High BrandNetwork
MG (SAIC)U0044Vehicle Communication Bus B High BrandNetwork
TataU0044Vehicle Communication Bus B (-) High BrandNetwork
ToyotaU0044Vehicle Communication Bus B High BrandNetwork

Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.

5Related codes

Browse Uxxx codes or U004xx codes.

OpenDTC - independent fault code reference