Where exactly are you getting that information from? Wherever it was, it's mostly wrong. While it may be possible, it is extremely unlikely. A failed purge valve could set a P0440 but you would have purge valve codes along with the P0440. I personally have never seen a purge valve cause a P0440, even when they've failed and are being replaced for other reasons. A P0440 is a large leak. This could be caused by a vent valve that is not closing/sealing when it should, preventing the system from drawing and holding a vacuum and passing the test. Obviously, it could be caused by genuine leaks in the system (such as something as simple as a gas cap that doesn't seal), but you need special equipment to test for this. I say replace the evap vent valve and go from there or take it somewhere that can do the proper tests to determine the cause.
There is a vent on top of the tank that's part of the tank, but the evap vent solenoid is a different thing. So, maybe they're not understanding what you're looking for. It is DEFINITELY available as a separate piece. The vent valve should be OPEN to flow when there is no power/ground applied to it. With the key ON, there should be power to the pink wire. The PCM then grounds the white wire as necessary to turn on the solenoid. You could try using an external ground on the white wire when the key's on to see if the solenoid clicks. They usually don't fail electrically but just get full of crud and fail to seal. Whether or not the vent valve is working, it should not affect the way the engine runs. A stuck open purge valve possibly but not the vent valve.
P0449 is an electrical problem with the evap vent solenoid and P0440 is "large leak detected" when the system runs the self-test. These tests are only run under very specific conditions, so you may get a light back on in 10 minutes after clearing the codes or 10 days. All depends on the various conditions that have to be met. Whoever told you the vent solenoid is part of the pump is smoking something really good. The vent solenoid is a totally separate entity and you need to speak to a parts department that knows what the hell they're doing. Either that or you're giving them some misinformation, which might be the case since other places are telling you the same thing. The P0449 *may* be due to a bad vent solenoid, but it's possible it's a wiring issue. Most likely culprit is the solenoid and if the solenoid is stuck open, you're gonna get the P0440. Pay no attention to the time period needed for the codes to set. Who told you the capacity of your tank is 22 gals? Short bed capacity is 26 gals. and long bed is 34 gals.
There's actually some logic in the P0116 DTC test that tries to determine if a block heater has been used. On the other hand, this is a type B code, which means the DTC test has to fail on two consecutive ignition cycles (in which the test runs) for it to turn the light on. So you're not in the clear yet on the light not coming on.
Instead of all this darn moanin' and groanin', just cut the d**n plug off and put a standard three prong plug on it and be done with it. If the SES light comes on, deal with it by leaving it on or have it checked and cleared every time.
Actually, we're already beggin' the newcomers to go back. The place is overflowing with people, growth is out of hand, my $135,000 house purchased 10 years ago would now cost me a half-million, and trust me, it's not what I would think of as a half-million dollar home. Roads are crammed like never before. Thank goodness I'm only a few miles from work and the opposite way traffic flows in the morning and night.
Chances are zero to none. This coolant temp rise test is a federal emission requirement. Talk to your legislators and see if you can get them to convince the EPA that you would like to have your truck warm when you start it up. GM has little say in this stuff. They have to certify the vehicle with the EPA and can't just change calibrations willy nilly. Any change that would affect emissions would have to go through the same certification process.
Yeah, it is a bigger deal than you realize. This is not GM's decision. They have to meet certain standards that define what tests are run, when, and what the results must be to be in compliance. They can't just tweak things to suit their (or your) needs. As for your question as to whether or not the light will come on.... yes, after the second consecutive failure. Here's the full details on the criteria that must be met for DTC P0116 to run and what happens if it fails. This test appears to be able to detect if a block heater is in use, in which case the test aborts, but perhaps under some conditions, it may fail the test anyway. --------- Conditions for Running the DTC • The ignition is ON. • DTCs P0112, P0113, P0116, P0117, P0118, P0128, P0502, P0503 are not set. • The start-up IAT is more than -7°C (+20°F). • The vehicle has a minimum ignition OFF time of 10 hours. • DTC P0116 runs once per drive cycle when the above conditions are met. Conditions for Setting the DTC • The start-up ECT is more than the start-up IAT by 100°C (180°F). OR • The start-up ECT is more than the start-up IAT by 15°C (27°F), then the vehicle must be driven for more than 400 seconds over 24 km/h (15 mph). If the IAT sensor temperature decreases more than 8°C (14°F), a block heater is detected and the test is aborted. If the IAT sensor temperature does not decrease, a block heater was not detected and DTC P0116 sets. Action Taken When the DTC Sets The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. Conditions for Clearing the MIL/DTC • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. • A current DTC, Last Test Failed, clears when the diagnostic runs and passes. • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. • Clear the MIL and the DTC with a scan tool.
Oh, there's someone at GM that knows the answer. It's just finding him or her. As for getting different answers based on the person contacted... is it really any different anywhere else? I don't think so. I've called on various topics from insurance problems (darn hurricanes) to tech licensing in Dade county. I get a different answer every time I've called! That's not to say that it shouldn't be that way.
I wouldn't rely on what one guy at Partech says anymore than I'd rely on what one of the guys at TAC says. I can talk to 3 different guys at TAC and get three different answers. It's really frustrating at times. Some of them are pretty sharp, others know little to nothing.
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