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P0455, stuck, please help

701 Views 7 Replies 3 Participants Last post by  jasons99hoe
Try to keep this short but give you a full history (2005 Suburban)

Few months back, wifes car became very hard to full with gas. No engine light on at this time.
replaced purge valve, vent solenoid, charcoal canister, and gas cap over the course of a few days. Charcoal canister had leaked charcoal bits into my evap lines so I used some compressed air to clear the lines.

P0455 comes on (gross leak)

Took the truck into a shop ran smoke test. They could not find a leak.
Replaced fuel tank pressure sensor and didnt fix issue
Mechanic Discovered that the vent solenoid was working intermittently. Replaced again ( I replaced before) but same issue remained.
The auto guy reported the solenoid would stay in the "venting" state and was unresponsive to the snap on tool trying to close it. He would disappear for 10 minutes or so and when he came back it would be working fine. When he tried to run the evap test, the computer would almost freeze up and the solenoid would not be able to close. He has never seen this before, wants me to take the truck to a chevy Dealer. As a note, he tried two different snap on diagnostic tools and same results

Any help here before I have to take this in? I am due for an inspection this month and not looking to spend over $1k at the dealer on this older suburban
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I have asked the owner of the shop and did not get a definitive response, rather just "i'm sure he checked it"

Is this something I can check my self without the diagnostic tool?
Is there a way to check the wiring (specifically ground) without having a diagnostic computer to hook up to the vehicle?
Pulled the connector from the solenoid today and inspecting it. No loose wires or fraying that I can see in the immediate vicinity of the connector.
I checked voltage and the hot wire gives me 12 volts, the ground wire nothing. My understanding is the ground wire should also be giving me 12 volts unless the pcm is trying to close the valve. Is my thinking correct? Next step trace the ground wire as far as I can go to see if I can find an issue?
Made a mistake, with the connector plugged into the solenoid, bout wires read 12v correctly. Just dont have a way to close the vent solenoid unless i can find a cheap scanner to do the trick.
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