U0121 on Chrysler
Lost Communication with ABS Module
U0121 on Chrysler vehicles indicates lost communication with abs module. Au7o has documented this code across 1 Chrysler model — most commonly on 300. U0121 is a network communication code meaning a control module on the vehicle's data bus has lost communication with the ABS (anti-lock brake system) module. Modern cars share information over a CAN bus, and when other modules stop receiving expected messages from the ABS unit, this code sets. Because the ABS module also handles traction control and stability control on most vehicles, you may see multiple warning lights and lost features. It points to a communication or power problem with the ABS module rather than a worn brake part. Typical repair costs on Chrysler range from $300 to $1,200, depending on the specific model and root cause.
Common Causes of U0121
- •Loss of power or ground to the ABS module
- •Blown fuse feeding the ABS controller
- •Damaged, corroded, or loose ABS module connector
- •Open, shorted, or chafed CAN bus wiring
- •Internal failure of the ABS control module
- •Corrosion or water intrusion in connectors/harness
- •Faulty gateway module disrupting bus communication
U0121 on Chrysler by Model
Chrysler 300(1 issue)
- ABS Module Internal Failure2011-2023
ABS control module suffers internal failures due to short circuits in main circuit board. Prevents proper ABS operation and stores fault codes. While regular braking functions, vehicle loses anti-lock capability, traction control, and stability control.
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View U0121 across all makes →Frequently Asked Questions
What does U0121 mean on Chrysler?▼
U0121 stands for "Lost Communication with ABS Module." U0121 is a network communication code meaning a control module on the vehicle's data bus has lost communication with the ABS (anti-lock brake system) module. Modern cars share information over a CAN bus, and when other modules stop receiving expected messages from the ABS unit, this code sets. Because the ABS module also handles traction control and stability control on most vehicles, you may see multiple warning lights and lost features. It points to a communication or power problem with the ABS module rather than a worn brake part. On Chrysler specifically, this code is documented across 1 model.
What causes U0121 on Chrysler vehicles?▼
Common causes on Chrysler: Loss of power or ground to the ABS module, Blown fuse feeding the ABS controller, Damaged, corroded, or loose ABS module connector, Open, shorted, or chafed CAN bus wiring, Internal failure of the ABS control module. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U0121 on a Chrysler?▼
Repair costs on Chrysler range from $300 to $1,200, depending on the specific model and root cause.
Which Chrysler models have U0121 documented?▼
Au7o has documented U0121 on 1 Chrysler model: 300.