Fault code lookup

NetworkU1166

Serious

Severity: Serious - have it checked soon

Loss of Communications with SCM

11 brands affected · Description from GM 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 11

BrandCodeDescriptionSystem
DaewooU1166Loss of Communications with SCM BrandNetwork
EOBDU1166Side kaotus SCM-ga BrandNetwork
GMU1166Loss of Communications with SCM BrandNetwork
HoldenU1166No description available Network
IsuzuU1166No description available Network
MitsubishiU1166EV-ECU lost BrandNetwork
OpelU1166Loss of Communications with SCM BrandNetwork
PeugeotU1166No description available Network
ProtonU1166EV-ECU lost BrandNetwork
SaabU1166Loss of Communications with SCM BrandNetwork
MG (SAIC)U1166Message Timeout 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.

5Related codes

Browse Uxxx codes or U116xx codes.

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