#Chevy pcm replacement update
#Chevy pcm replacement code

Confirmed by manually grounding this connection and listening to the valve click. There is far too much resistance between it and true battery ground. Checked ground with a test light.this wire will NOT carry a load. The PCM is not supposed to open the purge on engine start, so this is a problem.Д«ut what happens when I plug in the valve? Nothing. Test light confirms that this hot wire can carry a load (no high resistance fault due to damaged wiring). Key on, engine off, connector unplugged, I've got 12v on one side of the valve. I need to remove the upper intake stuff to be able to easily get to it and check the wiring, so that's what I do. It has to be the purge valve or its wiring. And I've pulled the hose off the charcoal canister to check for fuel (comes from 'topping off' the tank and flooding it). But I'm 99% sure it will pass this test, as I've found a different issue. I don't have the equipment to manually trigger it through the ECM, so I do need to do one more test concerning the ground wire to make sure the wiring is okay (ECM turns it on by grounding it). I spent hours going through this damn car. You could also have a vacuum leak on the engine intake side of the valve causing the leak, but this would generally set other DTC's or at least give some very telling data (fuel trim issues). But, as far as I can tell, this vehicle is not set up to monitor that.

#Chevy pcm replacement code

There's another code for no flow through the purge valve, much like there is for the EGR system. Possible causes: bad canister valve or wiring, a leak in the system, bad purge valve or wiring, saturated charcoal canister (has liquid fuel in it).that's about it, as far as I can think right now.

P0440 means either the requisite vacuum was never pulled on the evap system, or that said vacuum went away too quickly. Then the purge valve closes, and a pressure sensor monitors the system to check for malfunctions. Then the normally-open canister valve closes (allowing vacuum to be pulled on the evap system). Vapors are pulled by engine vacuum through the system and into the engine. When the evap monitor (self-test) runs on most vehicles: the normally-closed purge valve opens. If no one can help, hell, maybe I'll at least help someone else. I'll try and add in a little education here while also describing what I'm running into. Like most evap codes, it's a 'something is wrong with me but I don't know what' code. Okay, so I'm working on a 2001 Cavalier with the old 2.2L.

#Chevy pcm replacement update

Edit: this is old, just posted update at bottom in case anyone gives a shit.