Reductant Tank Heater A Control Circuit
The KUBOTA-P20B9 (Kubota) diesel fault code means: Reductant Tank Heater A Control Circuit. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $200-$600 heater
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Common Symptoms
- MIL in cold weather
- Possible frozen DEF slow-thaw
Probable Causes (Ranked by Likelihood)
- Open heater element Likely
- Blown heater fuse Likely
Step-by-Step Diagnostic Procedure
Ohm test tank heater (several ohms).
Check fuse F-xx (cab fuse panel).
Frequently Asked Questions
What is Kubota code P20B9?
Kubota P20B9 means: Reductant Tank Heater A Control Circuit. Moderate code -- address promptly to avoid inducement / further damage.
Can I keep using my Kubota with P20B9?
Moderate fault -- you can usually finish the job but plan repair soon. Use Kubota Diagmaster software (dealer tool) for full diagnostics.
How much does P20B9 cost to fix on a Kubota?
Repair cost range: $200-$600 heater. Compact-tractor labor is typically $110-$150/hr in 2026.