ABS Module Lab
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U0121

ABS / stability-control fault code, listed for 15 vehicle lines from Chevrolet, Chrysler, Dodge, Ford, Hyundai, Jeep, Land Rover, Mazda, Ram. What it means on each one, with sources, and when the module is the cause.

What U0121 means

Is it the ABS module?

Check the cheap things first: battery voltage and the main fuses for the ABS pump and module, the ground straps, the module connector (corrosion, a pushed-back pin) and, for wheel-speed codes, the sensor and its wiring at each wheel. If those are good and the code returns as soon as it is cleared — or the scan tool cannot talk to the ABS module at all — the module itself is the likely cause, and that is what we repair.

Vehicles that set U0121

U0121 by vehicle

What does U0121 mean on a Chevrolet Silverado 1500 (GMT900)?

The source we cite for the 2007-2014 Chevrolet Silverado 1500 (GMT900) lists it as: Lost Communication With Anti-Lock Brake System (ABS) Control Module. Repair starts at $499.

What does U0121 mean on a Chrysler 300 (LX/LD)?

The source we cite for the 2005-2020 Chrysler 300 (LX/LD) lists it as: Lost communication with ABS Module (a rebuilder 'Chrysler 300 2005-2014 ABS EBCM Anti-Lock Brake Control Module Repair Service'). That vehicle uses Mopar sells the ABS 'Module' separately from the 'Hydraulic Control Unit' for most years (e.g. 2008: module 68028992AA v. Repair starts at $499.

What does U0121 mean on a Dodge Grand Caravan (RT)?

The source we cite for the 2008-2020 Dodge Grand Caravan (RT) lists it as: Lost communication with ABS Module (a rebuilder 'Chrysler Town Country 2007-2011 ABS EBCM Anti-Lock Brake Control Module Repair Service'). Repair starts at $499.

What does U0121 mean on a Dodge Journey (JC)?

The source we cite for the 2009-2020 Dodge Journey (JC) lists it as: Listed by a rebuilder for the 2016-2020 Journey alongside 'communication errors' (lost communication with the ABS module). Repair starts at $499.

What does U0121 mean on a Ford F-150 (2007-2008)?

The source we cite for the 2007-2014 Ford F-150 (2007-2008) lists it as: Lost Communication With Anti-Lock Brake System (ABS) Control Module (listed by a rebuilder). That vehicle uses Bosch Bosch 8.0 ABS with stability control (VSC); 2007-2008 also Bosch 8.1 ('mini 8.0'). We repair it as part of the Bosch ABS / ESP 8 family, from $499.

What does U0121 mean on a Hyundai Genesis sedan (BH) 2009-2014?

The source we cite for the 2009-2016 Hyundai Genesis sedan (BH) 2009-2014 lists it as: Lost communication with ABS module. That vehicle uses MK61 ABS module (rebuilder designation). We repair it as part of the ATE / Continental MK60 / MK61 family, from $499.

Still not sure?

Send us U0121, a photo of the module label and your VIN — we tell you whether the module is the likely cause and what it costs, before you pull anything. Asking costs nothing.

Ask First — Send a Label PhotoStart My Repair — from $499

U0121 keeps coming back after the checks? Fix the module — from $499.

Look up your part number and order online — we email you a prepaid label to our lab. Or send us a photo of the label and your VIN first, and we'll tell you what you have and what it costs.

Back with your VIN and coding · can’t be repaired? repair price back, minus shipping · 1-year warranty · rush 2–3 days +$100

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Call (817) 505-4201 · 📱 Text us a photo of the module label · Ask first — send a label photo · Email repairs@absmodulelab.com