OBD Guide

U1091

Invalid Or Missing Data For Non-Legislated Diagnostics

U1091 is an OBD-II diagnostic trouble code meaning: Invalid Or Missing Data For Non-Legislated Diagnostics. Common causes: problems with the can bus (open or short circuit), malfunction of one of the electronic modules. Estimated repair cost: ~$278.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
~$278 (est.)

Symptoms

  • Check Engine light comes on
  • Problems connecting diagnostic equipment
  • Some non-essential vehicle functions do not work
  • Intermittent failures in the infotainment system

Causes

  • Problems with the CAN bus (open or short circuit)
  • Malfunction of one of the electronic modules
  • Problems with module software
  • Poor contact in CAN bus connectors
  • After flashing or replacing the module

How to Fix

  1. Check the integrity of the CAN bus and the connection of connectors
  2. Read all error codes to identify the problematic module
  3. Update module software (if available)
  4. Check the power and grounding of the problematic module
  5. If necessary, replace the faulty module

Related codes

FAQ

What does the U1091 code mean?

U1091 is an OBD-II diagnostic trouble code that indicates: Invalid Or Missing Data For Non-Legislated Diagnostics

What causes a U1091 error code?

The most common causes of U1091 include: Problems with the CAN bus (open or short circuit); Malfunction of one of the electronic modules; Problems with module software; Poor contact in CAN bus connectors.

How do I fix a U1091 diagnostic trouble code?

To fix U1091: Check the integrity of the CAN bus and the connection of connectors. Read all error codes to identify the problematic module. Update module software (if available). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1091?

Yes, but get it checked soon

How much does it cost to fix U1091?

The estimated repair cost for U1091 is ~$278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat