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U0121

Overview

Code

U0121

Code Type

U

Code Class

U0

System

Network

Severity Level

Medium

Emissions Related

false

Drivability Impact

Minor

Diagnostic Protocol

CAN

Freeze Frame Useful

false

Code Definition

Diagnostic trouble code U0121 indicates lost communication with the ABS control module

Symptoms

ABS warning light

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

ABS and stability control communication

Possible Causes

ABS module power loss

Diagnostic Steps

1 Check ABS module power 2 Inspect CAN bus lines

Drive Safety Notes

ABS and traction control disabled

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