Fault code lookup

NetworkU1111

Serious

Severity: Serious - have it checked soon

Lost communication (IDM)

30 brands affected · Description from Toyota data.

Key terms: Control module: a small computer that runs one part of the car

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 30

BrandCodeDescriptionSystem
Mercedes-BenzU1111No description available Network
BYDU1111Display CAN timeout/Not equipped BrandNetwork
CheryU1111Display CAN timeout/Not equipped BrandNetwork
ChryslerU1111lost odometer message BrandNetwork
DaewooU1111Loss of serial communications for class 2 devices BrandNetwork
DaihatsuU1111Fr sonar ECU communication error BrandNetwork
DFFSU1111Ccan_GW33A_AmbTemp message is invalid BrandNetwork
DFFXU1111Display CAN timeout/Not equipped BrandNetwork
EOBDU1111Kaotatud side BrandNetwork
GeelyU1111Display CAN timeout/Not equipped BrandNetwork
GMU1111Loss of serial communications for class 2 devices BrandNetwork
Great WallU1111Display CAN timeout/Not equipped BrandNetwork
HafeiU1111Display CAN timeout/Not equipped BrandNetwork
HoldenU1111Lost Communication with Battery Energy Control Module BrandNetwork
HyundaiU1111No description available Network
IsuzuU1111No description available Network
MahindraU1111No description available Network
MitsubishiU1111Display CAN timeout/Not equipped BrandNetwork
NissanU1111No description available Network
OpelU1111Loss of serial communications for class 2 devices BrandNetwork
PeroduaU1111Fr sonar ECU communication error BrandNetwork
PeugeotU1111No description available Network
ProtonU1111Display CAN timeout/Not equipped BrandNetwork
SaabU1111Loss of serial communications for class 2 devices BrandNetwork
MG (SAIC)U1111Loss Communication With BMS BrandNetwork
SmartU1111No description available Network
SprinterU1111No description available Network
SuzukiU1111No description available Network
ToyotaU1111Lost communication (IDM) BrandNetwork
VolkswagenU1111Function restricted due to missing message(s); Short to ground 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.

5Extended variant codes 3

These 7-character codes are manufacturer-specific variants of U1111 and may be reported by some scan tools.

BrandCodeDescriptionSystem
HyundaiU111100If LIN message from battery sensor is not received, ECM sets DTC BrandNetwork
VolkswagenU111100Functional impairment due to missing message BrandNetwork
SsangYongU111102CAN communication: EVCC_342 communication error - timeout BrandNetwork

6Related codes

Browse Uxxx codes or U111xx codes.

OpenDTC - independent fault code reference