P0448 Nissan - frontier

Question

Code po448. Descripon "evaporative emission system vent control circuit shorted". I have taken off all solenoids related to evap system and checked them using ohm meter, and a fused jumper cable. All solenoids Work as they should. I have also checked all fuses, and all relays. I don't know if the circuit is an actual circuit like computer board or if it's the harness. Is this an actual short or is this just what comes up under this code. How do I find the short. Is there a short. How do,i diagnose or fix this? Please help

Answer 1

Hi there

This code is for the vent control valve on the charcoal canister. IF it's working when you test it, then you need to check the harness for power and ohm the wire from the vcv to the ecm. The ecm uses a ground signal to open and close the valve. If there is a short to ground on the signal wire, it could be holding the valve closed.