P0499

EVAP System Vent Valve Control Circuit High

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$33–89 (est.)

Symptoms

Check Engine Light Is On
Poor engine performance at idle
Increased fuel consumption
Unstable engine operation

Causes

Short circuit in the valve circuit to +12V
Open circuit in valve control circuit
Purge solenoid valve malfunction
Problems in the wiring harness
Engine ECU malfunction

How to Fix

Check the integrity of the wiring harness to the valve
Measure the valve resistance (should be between 20-50 Ohms)
Check the voltage at the valve connector with the ignition on
Check the circuit for a short circuit to ground or +12V
If necessary, replace the EVAP purge valve

Related codes

P0440 P0441 P0442 P0446 P0455