NetworkU0438

Serious

Severity: Serious - have it checked soon

Invalid data received from trailer brake control module

23 brands affected · Description from Toyota data.

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

Safety: This code relates to the braking system. Have braking checked promptly.

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 23

Brand	Code	Description	System
Ashok Leyland CV	U0438	No description available	Network
BAIC Motor	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
BYD	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Chery	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Daewoo	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
DFFS	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
DFFX	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
DFXK	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
EOBD	U0438	Ugyldige data modtaget fra trailerbremsestyremodul Brand	Network
Geely	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
GM	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Great Wall	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Hafei	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Holden	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Hyundai	U0438	No description available	Network
Land Rover	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Maserati	U0438	Implausible data received from trailer control module Brand	Network
Opel	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Peugeot	U0438	No description available	Network
Porsche	U0438	No description available	Network
Saab	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
MG (SAIC)	U0438	Invalid Data Received From Trailer Brake Control Module Brand	Network
Toyota	U0438	Invalid data received from trailer brake control module 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 6

These 7-character codes are manufacturer-specific variants of U0438 and may be reported by some scan tools.

Brand	Code	Description	System
Mercedes-Benz	U043800	Das FlexRay-Signal Trlr_Stat (Anhängerkupplung) vom TM-SG ist fehlerhaft. Brand	Network
Mercedes-Benz	U043829	Das Signal SIG_Trlr_Stat_ST3 vom Anhänger-SG BCF_TrlrHtch wird mit einem ungültigem Wert empfangen Brand	Network
Mercedes-Benz	U043841	Botschaften vom BCF-Steuergerät (TrlrHtch) zeigen einen Fehler im Botschaftszähler oder CRC-Fehler Brand	Network
Mercedes-Benz	U043882	Botschaften vom BCF_TrlrHtch führen in der IDC zu einem kumulierten Fehler. Brand	Network
Mercedes-Benz	U0438E0	Das Signal SIG_Trlr_Stat_ST3 wird mit einem ungültigem Wert empfangen Brand	Network
Mercedes-Benz	U0438E1	Botschaft vom BC_F SG wird zeitweise nicht empfangen Brand	Network

6Related codes

Browse Uxxx codes or U043xx codes.