enbgde
P2028 Generic (SAE) Basic entry

Evaporative Emissions (EVAP) Fuel Vapor Temperature Sensor Circuit Intermittent

Updated 2026-10-02 · Fuel, air & emissions (P2)

Severity
Low
Typical repair cost
40 – 350 EUR
System
Powertrain

What it means

P2028 is stored when the Evaporative Emissions (EVAP) Fuel Vapor Temperature signal drops out or jumps erratically for short periods. Intermittent faults are almost always connector, wiring or vibration related.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

Advertisement728 × 90

Symptoms

  • Check engine light on
  • Rough or unstable idle
  • Hesitation or poor acceleration
  • Increased fuel consumption
  • Possible limp mode with reduced power

Common causes

  1. Damaged, chafed or corroded wiring in the Evaporative Emissions (EVAP) Fuel Vapor Temperature circuit
  2. Corroded, loose or water-damaged connector terminals
  3. Failed Evaporative Emissions (EVAP) Fuel Vapor Temperature component (sensor, solenoid or actuator)
  4. Poor ground connection for the module or component
  5. Faulty control module driver (rare, confirm all else first)

How to diagnose

  1. Read freeze frame data and note when the code set (cold start, under load, after rain)
  2. Inspect the Evaporative Emissions (EVAP) Fuel Vapor Temperature connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
  3. Measure supply voltage and ground at the connector with the key on
  4. Check the signal wire for shorts to ground or battery and for continuity to the control module
  5. Test or substitute the Evaporative Emissions (EVAP) Fuel Vapor Temperature only after wiring and connectors are confirmed good
  6. Clear the code and complete a drive cycle to confirm the repair

Frequently asked questions

Can I keep driving with P2028?

Yes. The fault does not affect safety or driveability, but it will keep the warning light on and may fail an inspection.

Will clearing P2028 fix it?

No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.

Related codes

P2025P2026P2027

Nearby codes in this group