U0121 on Ford
Lost Communication with ABS Module
U0121 on Ford vehicles indicates lost communication with abs module. Au7o has documented this code across 1 Ford model — most commonly on Transit. 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 Ford range from $250 to $3,200, 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 Ford by Model
Ford Transit(1 issue)
- Electric Power Steering (EPAS) Assist Loss / Steering Fault Warnings2015-2020
NHTSA complaints include intermittent or sudden loss of power steering assist with warning messages, making the van difficult to steer at low speeds. Reports often describe the issue occurring after a restart, during parking maneuvers, or intermittently with electrical/communication faults. The Transit’s EPAS system can set steering-related DTCs and may require module diagnosis or replacement depending on root cause.
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View U0121 across all makes →Frequently Asked Questions
What does U0121 mean on Ford?▼
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 Ford specifically, this code is documented across 1 model.
What causes U0121 on Ford vehicles?▼
Common causes on Ford: 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 Ford?▼
Repair costs on Ford range from $250 to $3,200, depending on the specific model and root cause.
Which Ford models have U0121 documented?▼
Au7o has documented U0121 on 1 Ford model: Transit.