Lost Communication with ABS Module
The KUBOTA-U0121 (Kubota) diesel fault code means: Lost Communication with ABS Module. This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- advanced
- Estimated cost
- $400-$1,200 ABS module
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Common Symptoms
- ABS lamp
- Brake assist disabled
Probable Causes (Ranked by Likelihood)
- Failed ABS module (M7 class) Possible
- CAN wiring damage Likely
Step-by-Step Diagnostic Procedure
Scan bus with Diagmaster.
Check module power/ground.
Frequently Asked Questions
What is Kubota code U0121?
Kubota U0121 means: Lost Communication with ABS Module. Serious code -- address promptly to avoid inducement / further damage.
Can I keep using my Kubota with U0121?
Serious fault -- you can move the machine to a shop but don't run it under load. Use Kubota Diagmaster software (dealer tool) for full diagnostics.
How much does U0121 cost to fix on a Kubota?
Repair cost range: $400-$1,200 ABS module. Compact-tractor labor is typically $110-$150/hr in 2026.
U0121 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: