Fault code lookup

NetworkU3003

Serious

Severity: Serious - have it checked soon

Battery Voltage

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

Safety: This code relates to the charging system. The battery may go flat and the car may stall.

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 29

BrandCodeDescriptionSystem
Ashok Leyland CVU3003Battery Voltage SAENetwork
BAIC MotorU3003Battery Voltage BrandNetwork
BYDU3003Battery Voltage BrandNetwork
CheryU3003Battery Voltage BrandNetwork
DaewooU3003Battery Voltage BrandNetwork
DFFSU3003Battery Voltage BrandNetwork
DFFXU3003Battery Voltage BrandNetwork
DFXKU3003Battery Voltage BrandNetwork
EOBDU3003Accuspanning BrandNetwork
FordU3003DTC: 16 set - Battery Voltage Low BrandNetwork
GeelyU3003CAN voltage BrandNetwork
GMU3003Battery Voltage BrandNetwork
Great WallU3003Battery Voltage BrandNetwork
HafeiU3003Battery Voltage BrandNetwork
HoldenU3003Battery Voltage BrandNetwork
HondaU3003Battery Voltage SAENetwork
HyundaiU3003Battery Voltage SAENetwork
Land RoverU3003Battery Voltage SAENetwork
MazdaU3003DTC: 16 set - Battery Voltage Low BrandNetwork
MitsubishiU3003Battery Voltage SAENetwork
OpelU3003Battery Voltage BrandNetwork
PeugeotU3003Battery Voltage SAENetwork
ProtonU3003Battery Voltage SAENetwork
SaabU3003Battery Voltage BrandNetwork
Maxus (SAIC)U3003Battery voltage low BrandNetwork
MG (SAIC)U3003Battery Voltage BrandNetwork
TataU3003Battery Voltage SAENetwork
ToyotaU3003Battery voltage too high or too low BrandNetwork
VolkswagenU3003Battery Voltage SAENetwork

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 2

These 7-character codes are manufacturer-specific variants of U3003 and may be reported by some scan tools.

BrandCodeDescriptionSystem
Mercedes-BenzU300300SPT stopped by external reason (Safety) BrandNetwork
Land RoverU300362No description available Network

6Related codes

  • U3000 Control Module
  • U3001 Control Module Improper Shutdown Performance
  • U3002 Vehicle Identification Number
  • U3004 Accessory Power Relay
  • U3005 Retained Accessory Power
  • U3006 Control Module Input Power A Circuit/Open
  • U3007 Control Module Input Power B Circuit/Open
  • U3008 Control Module Ground A
  • U3009 Control Module Ground B
  • U300A Ignition Switch
  • U300B Ignition Input Accessory/On/Start
  • U300C Ignition Input Off/On/Start

Browse Uxxx codes or U300xx codes.

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