NetworkU1401

Serious

Severity: Serious - have it checked soon

Scope present in vehicle - Connect connector to COMAND controller unit

33 brands affected · Description from Mercedes-Benz 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 33

Brand	Code	Description	System
BAIC Motor	U1401	Immobilizer communication fault Brand	Network
Mercedes-Benz	U1401	Scope present in vehicle - Connect connector to COMAND controller unit Brand	Network
BYD	U1401	Dynamic Range Error Brand	Network
Chery	U1401	Dynamic Range Error Brand	Network
Chrysler	U1401	RBM fault Brand	Network
Daewoo	U1401	Brake Switch Circuit Malfunction Brand	Network
DFFS	U1401	CAN IS network failure Brand	Network
DFFX	U1401	Dynamic Range Error Brand	Network
DFXK	U1401	Immobilizer communication error Brand	Network
EOBD	U1401	LIN-linje Brand	Network
Fiat	U1401	Implausible engine speed signal received Brand	Network
Geely	U1401	Dynamic Range Error Brand	Network
GM	U1401	No description available	Network
Great Wall	U1401	Dynamic Range Error Brand	Network
Hafei	U1401	Dynamic Range Error Brand	Network
Holden	U1401	Lost Communication With Generator Control Module Brand	Network
Honda	U1401	No description available	Network
Hyundai	U1401	No description available	Network
Isuzu	U1401	No description available	Network
Mahindra	U1401	No description available	Network
Maserati	U1401	implausible engine speed signal received Brand	Network
Mitsubishi	U1401	LIN communication Brand	Network
Opel	U1401	No description available	Network
Peugeot	U1401	No description available	Network
Proton	U1401	LIN communication Brand	Network
Saab	U1401	No description available	Network
MG (SAIC)	U1401	Engine Torque Signal Error Brand	Network
Smart	U1401	No description available	Network
Sprinter	U1401	Scope present in vehicle - Connect connector to COMAND controller unit Brand	Network
Subaru	U1401	No description available	Network
Suzuki	U1401	Invalid Data Received From ECM/PCM “A” – Rolling Counter Error Brand	Network
Toyota	U1401	Vehicle control unit (VCU) internal fault Brand	Network
Volkswagen	U1401	Functional impairment due to high voltage 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 4

These 7-character codes are manufacturer-specific variants of U1401 and may be reported by some scan tools.

Brand	Code	Description	System
SsangYong	U140100	CAN: engine speed (from MS) not available Brand	Network
Volkswagen	U140100	Functional impairment due to Brand	Network
Mercedes-Benz	U140142	Das Signal PN14_SecSup_Det_ST3 oder PN14_SecSup_Stat_ST3 wird mit einem ungültigem Wert empfangen Brand	Network
Mercedes-Benz	U140186	The signal 'engine rpm' from control unit 'combustion engine' was not received. Signal Invalid Brand	Network

6Related codes

Browse Uxxx codes or U140xx codes.