U0640

Lost Communication With EVAP Fuel Vapor Temperature Sensor Circuit

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–50 (est.)

Symptoms

Check Engine light is on
Problems starting the engine
Increased fuel consumption
Unpleasant smell of gasoline
Dips during acceleration

Causes

EVAP temperature sensor circuit open
Short circuit in wiring harness
Fuel vapor temperature sensor malfunction
Bad contacts in connectors
Problems with the engine control unit

How to Fix

Check the integrity of the wiring harness to the sensor
Inspect and clean the connector contacts
Check the resistance of the temperature sensor
Replace the fuel vapor temperature sensor if necessary
Scan the ECU for additional errors

Related codes

U0639 U0641 U0642