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U030A Software Incompatibility With Evaporative Emission System Leak Detection Control Module

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

In some evaporative systems a dedicated module with its own pump or valve, pressure switch and electronics runs the leak test. U030A means that controller has found the module's software or calibration not to fit. No manufacturer documents U030A publicly. Kia's 2017-2019 Niro hybrid uses such a natural vacuum leak detection unit: its lost-communication code U029F00 lit the MIL, and bulletin PS593 traced it to a damaged signal wire at the NVLD connector. Ford's 2014 code interpretation gives U029F the MIL marker as well. CARB demands the leak monitor, so a mismatch that blocks or falsifies it is emission-relevant and a MIL is probable. The car drives normally; the EVAP readiness flag may remain incomplete, which can fail an inspection. U029F is the lost-contact code.

Likely causes

Leak detection module replaced with a unit of another part number
Engine controller reprogrammed with a calibration that expects other module software
Damaged signal wire corrupting the identification exchange

Symptoms

  • MIL on, usually without any drivability change
  • EVAP readiness monitor not completed
  • Further EVAP leak test codes may follow

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–500
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

evap leak detection modulecontrol module software

Related codes

U029FP0455P0456U0301

References: static.nhtsa.gov, performanceparts.ford.com, law.cornell.edu.