Hello again all!
As i stated before I have tje engine light display ! Also the fuel cap message ( have replaced fuel cap and still get message) as well as tpms message!

I plugged in a wi-fi obdII and got the error code and description .. any ideas ?


P0455
Evaporative Emission Control System Tank Detected (large leak)

Status of this DTC
Confirmed DTC

Engine state when the fault appeared
Freeze frame trouble code: P0455
Fuel system status 1: Closed loop
Fuel system status 2: Unused
Calculated load value: 25.5 %
Coolant temperature: 92 °C
Short term fuel % trim Bank 1: 0.0 %
Long term fuel % trim Bank 1: +7.0 %
Intake Manifold Pressure: 0.36 bar
Engine RPM: 620 rpm
Vehicle speed: 0 km/h
Timing advance: 11.0 °
Intake air temperature: 12 °C
Maf air flow: 4.14 g/s
Absolute Throttle sensor position: 15.7

 

Search Vent Valve Canister

Here is an old thread about your code, you can check the wiring at the connector which is always a possibility. Look at page two, there are links to the part for a cheap fix. https://www.hummerforums.com/forum/h...-needed-24205/