Fault code lookup

NetworkU1103

Serious

Severity: Serious - have it checked soon

Production mode 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

  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 31

BrandCodeDescriptionSystem
BAIC MotorU1103Received TCU signal abnormal BrandNetwork
Mercedes-BenzU1103No description available Network
BYDU1103Lost communication with SRS BrandNetwork
CheryU1103PDC CAN timeout/Not equipped BrandNetwork
DaewooU1103Loss of serial communications for class 2 devices BrandNetwork
DaihatsuU1103Idle stop ECU BrandNetwork
DFFXU1103PDC CAN timeout/Not equipped BrandNetwork
EOBDU1103Üretim modu BrandNetwork
GeelyU1103PDC CAN timeout/Not equipped BrandNetwork
GMU1103Loss of serial communications for class 2 devices BrandNetwork
Great WallU1103PDC CAN timeout/Not equipped BrandNetwork
HafeiU1103PDC CAN timeout/Not equipped BrandNetwork
HoldenU1103No description available Network
HondaU1103No description available Network
HyundaiU1103No description available Network
IsuzuU1103No description available Network
MahindraU1103No description available Network
MitsubishiU1103ASC timeout/Not equipped BrandNetwork
OpelU1103Loss of serial communications for class 2 devices BrandNetwork
PeroduaU1103Idle stop ECU BrandNetwork
PeugeotU1103No description available Network
PorscheU1103No description available Network
ProtonU1103ASC timeout/Not equipped BrandNetwork
SaabU1103Loss of serial communications for class 2 devices BrandNetwork
MG (SAIC)U1103CAN configuration mismatch BrandNetwork
SmartU1103No description available Network
SprinterU1103No description available Network
SuzukiU1103No description available Network
TataU1103ECU Interior Communication Abnormal/Communication Error A BrandNetwork
ToyotaU1103Production mode active BrandNetwork
VolkswagenU1103Production Mode active; Short to ground BrandNetwork

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 U1103 and may be reported by some scan tools.

BrandCodeDescriptionSystem
PorscheU110300No description available Network
VolkswagenU110300Production mode active BrandNetwork
SsangYongU110302CAN communication: BS_20A communication error - timeout BrandNetwork
SsangYongU110317Battery voltage value too high BrandNetwork
SsangYongU110387CAN communication: Vehicle Control Unit (VCU) message not received BrandNetwork

6Related codes

Browse Uxxx codes or U110xx codes.

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