NetworkU0421

Serious

Severity: Serious - have it checked soon

Invalid Data Received From Suspension Control Module A

29 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

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 29

Brand	Code	Description	System
Ashok Leyland CV	U0421	Hybrid Battery. (Contactor. Positive Pole.) - Stuck Open Brand	Network
BAIC Motor	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Mercedes-Benz	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
BYD	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Chery	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Daewoo	U0421	Invalid Data Received From Suspension Control Module Brand	Network
DFFS	U0421	Invalid Data Received From Suspension Control Module Brand	Network
DFFX	U0421	Invalid Data Received From Suspension Control Module Brand	Network
DFXK	U0421	Invalid Data Received From Suspension Control Module Brand	Network
EOBD	U0421	Vigased andmed saadud riputuskontrollmoodulilt 'A' Brand	Network
Geely	U0421	Invalid Data Received From Suspension Control Module Brand	Network
GM	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Great Wall	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Hafei	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Holden	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Honda	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
Hyundai	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
Land Rover	U0421	Invalid data received from ride level control module Brand	Network
Maserati	U0421	Implausible Data Received From Suspension Control Module Brand	Network
Opel	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Peugeot	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
Porsche	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
Saab	U0421	Invalid Data Received From Suspension Control Module Brand	Network
MG (SAIC)	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Sprinter	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
Subaru	U0421	Invalid Data Received From Suspension Control Module A SAE	Network
Tata	U0421	Invalid Data Received From Ride Level Control Module Brand	Network
Toyota	U0421	Invalid Data Received From Suspension Control Module Brand	Network
Volkswagen	U0421	Implausible data received from ride level control module; Short to ground 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 U0421 and may be reported by some scan tools.

Brand	Code	Description	System
Mercedes-Benz	U042129	Das Signal INP_SPC_Flt_Stat wird mit einem ungültigem Wert empfangen Brand	Network
Mercedes-Benz	U042182	Botschaften vom SPC-Steuergerät zeigen einen Fehler im Botschaftszähler oder CRC-Fehler Brand	Network
Mercedes-Benz	U0421E0	Die Signale SPC_ECU_Stat_ST3 oder SPC_Flt_Stat_ST3 des SPC-Steuergerätes zeigen einen Fehler an Brand	Network
Mercedes-Benz	U0421E1	Das Signal INP_SPC_Flt_Stat wird mit einem ungültigem Wert empfangen Brand	Network
Mercedes-Benz	U0421E2	Botschaft vom EIS SG wird zeitweise nicht empfangen Brand	Network

6Related codes

Browse Uxxx codes or U042xx codes.