P2026: EVAP Fuel Vapor Temperature Sensor Circuit Low Voltage

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.

Low severity. Can I keep driving?Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

Symptoms

Check engine lamp on
Implausibly high vapor temperature in live data

Most likely causes

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

What to check, in order

Start with the simplest. You can tick off each step.

Start with the fuel cap: tighten it fully and check its seal
With the connector unplugged, check whether the signal wire is making contact with ground.
Inspect the hoses and connections around the tank and the charcoal canister
Use the scanner to test the purge and vent solenoid valves
Run a smoke test to find small leaks

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P2026 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
0: Subsystem depends on the code range
26: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2026?

Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

What causes code P2026?

The most common causes are: sensor signal wire shorted to ground; temperature sensor or leak detection unit shorted internally; moisture bridging pins at the canister-mounted connector.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.