NetworkU1101

Serious

Severity: Serious - have it checked soon

Component protection active

31 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

Wiring or connector fault on the communication bus
Faulty control module
Low battery voltage or poor ground
Water ingress in a connector or module
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 31

Brand	Code	Description	System
BAIC Motor	U1101	Voltage too low Brand	Network
Mercedes-Benz	U1101	No description available	Network
BYD	U1101	Communication fault Brand	Network
Chery	U1101	T/M CAN timeout/Not equipped Brand	Network
Daewoo	U1101	Loss of serial communications for class 2 devices Brand	Network
Daihatsu	U1101	ACC reception error Brand	Network
DFFX	U1101	T/M CAN timeout/Not equipped Brand	Network
EOBD	U1101	Komponentskydd aktivt Brand	Network
Geely	U1101	T/M CAN timeout/Not equipped Brand	Network
GM	U1101	Loss of serial communications for class 2 devices Brand	Network
Great Wall	U1101	T/M CAN timeout/Not equipped Brand	Network
Hafei	U1101	T/M CAN timeout/Not equipped Brand	Network
Holden	U1101	Lost Communication with Infotainment Control Touchpad Brand	Network
Honda	U1101	No description available	Network
Hyundai	U1101	No description available	Network
Isuzu	U1101	No description available	Network
Land Rover	U1101	Control Module Internal CAN Hardware Brand	Network
Mahindra	U1101	No description available	Network
Mitsubishi	U1101	EV ECU CAN timeout Brand	Network
Opel	U1101	Loss of serial communications for class 2 devices Brand	Network
Perodua	U1101	ACC reception error Brand	Network
Peugeot	U1101	No description available	Network
Proton	U1101	EV ECU CAN timeout Brand	Network
Saab	U1101	Loss of serial communications for class 2 devices Brand	Network
MG (SAIC)	U1101	Timeout A/T related Data Brand	Network
Smart	U1101	No description available	Network
Sprinter	U1101	No description available	Network
Subaru	U1101	No description available	Network
Suzuki	U1101	Lost communication with TCM or TCM (Automated Manual Transaxle) Brand	Network
Tata	U1101	CAN Communication Brand	Network
Toyota	U1101	Component protection active Brand	Network

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 5

These 7-character codes are manufacturer-specific variants of U1101 and may be reported by some scan tools.

Brand	Code	Description	System
SsangYong	U110100	CAN communication: Battery Management System (BMS) communication error - timeout Brand	Network
SsangYong	U110108	CAN bus: CAN bus off Brand	Network
SsangYong	U110116	Electric Heating, Ventilation, and Air Conditioning (EHVC) 12 V supply voltage low Brand	Network
SsangYong	U110117	Electric Heating, Ventilation, and Air Conditioning (EHVC) 12 V supply voltage high Brand	Network
SsangYong	U110131	CAN communication: Smart Key Module (SKM) FOB searching signal error Brand	Network

6Related codes

Browse Uxxx codes or U110xx codes.