Powertrain, generic (extended)

P2024 EVAP Fuel Vapor Temperature Sensor Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

The fuel vapor temperature sensor tells the ECM how warm the vapor in the tank and canister is, which matters for leak tests that judge pressure or vacuum as the fuel cools after shutdown. P2024 is the unspecified electrical code for that circuit. On recent Audi models the sensor is built into the leak detection unit J909 at the charcoal canister. An Audi bulletin first issued in 2023 and revised in September 2026 covers 2022–2025 A3 to Q8 models: four-cylinder engines could store P2024, described as an electrical fault of the tank breather temperature sensor, although guided diagnosis expects P2026 for a low voltage at J909. The fix there is to follow the corrected test, not to replace parts. Without valid temperature the EVAP leak test cannot complete.

Likely causes

Open or shorted wiring to the temperature sensor or leak detection unit
Misassigned fault entry in the ECM software (Audi 2022–2025)
Leak detection unit with integrated sensor faulty

Symptoms

  • Check engine lamp on
  • EVAP readiness not set, possible inspection failure

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–400
Time0.3–2 h

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

Parts involved

evap fuel vapor temp sensorevap leak detection moduleevap harness

Related codes

P2025P2026P2027P2028P0450

References: static.nhtsa.gov, law.cornell.edu.