Fault code lookup

NetworkU1202

Serious

Severity: Serious - have it checked soon

MCU CAN communication error 2

20 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 20

BrandCodeDescriptionSystem
BYDU1202Straight G sensor parity error BrandNetwork
CheryU1202Straight G sensor parity error BrandNetwork
DaewooU1202Loss of serial communications for class 2 devices BrandNetwork
DFFXU1202Straight G sensor parity error BrandNetwork
EOBDU1202Databusdiagnose BrandNetwork
GeelyU1202TCU Bus Off Fault BrandNetwork
GMU1202Loss of serial communications for class 2 devices BrandNetwork
Great WallU1202Straight G sensor parity error BrandNetwork
HafeiU1202Straight G sensor parity error BrandNetwork
HoldenU1202No description available Network
HondaU1202No description available Network
IsuzuU1202No description available Network
MahindraU1202No description available Network
MitsubishiU1202Straight G sensor parity error BrandNetwork
OpelU1202Loss of serial communications for class 2 devices BrandNetwork
PeugeotU1202No description available Network
ProtonU1202Straight G sensor parity error BrandNetwork
SaabU1202Loss of serial communications for class 2 devices BrandNetwork
SubaruU1202No description available Network
ToyotaU1202MCU CAN communication error 2 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 3

These 7-character codes are manufacturer-specific variants of U1202 and may be reported by some scan tools.

BrandCodeDescriptionSystem
SsangYongU120200CAN Bus-Off BrandNetwork
SsangYongU120201Active Grille Shutter (AGS) communication failure BrandNetwork
SsangYongU120288CAN communication: E-CAN no communication - bus off BrandNetwork

6Related codes

Browse Uxxx codes or U120xx codes.

OpenDTC - independent fault code reference