Powertrain, generic (extended)

P2026 EVAP Fuel Vapor Temperature Sensor Circuit Low Voltage

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2026 reports a vapor temperature signal stuck near 0 V. With the usual NTC thermistor and pull-up resistor, a low voltage corresponds to an extremely hot reading, so the code nearly always points to a signal wire touching ground or a shorted sensor rather than real heat. Audi names this test explicitly: on 2022–2025 models with four-cylinder engines, guided diagnosis checks P2026 as a too-low voltage at the temperature sensor inside leak detection unit J909, the result an earlier software wrongly filed as P2024. Ford's 2014 code list includes P2026 as a MIL-on fault. No public source gives a numeric threshold. Because the EVAP leak checks use this temperature, they are suspended until the circuit is repaired and the monitor has run again.

Likely causes

Sensor signal wire shorted to ground
Temperature sensor or leak detection unit shorted internally
Moisture bridging pins at the canister-mounted connector

Symptoms

  • Check engine lamp on
  • Implausibly high vapor temperature in live data

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–400
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

P2024P2025P2027P2028

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