one more P0445 Short to ground error

[valfam]

Hello my friends 99 996 started getting this error a few week ago I remember hearing a clicking sound from the valve when the engine was running. P0445 {Solenoid valve 2 for carbon canister Short to ground} I replaced the tank vent valve thats the valve thats located in the back by the intake. Keep in mind my friend did not buy the OEM one he bought one that looks the same but without the little quick connect hose on it. he is still getting the error code. Any ideas where I should look? is there away I can test the whole system. I'm thinking of taking every hose and valve apart and testing each one. Oh by the way it does have a new gas cap. he did tell me tonight that if when he is getting gas he cant run the pump at full speed it shut off on him he told me that if he runs the pump at 75% its fine. thanks in advance for any and all help.

[Ahsai]

Is the new EVAP purge valve clicking?

Edited December 19, 2013 by Ahsai

[valfam]

I don't think it is. I'm not sure. I have not heard it like the old one. Why do you ask?

Let me add one more thing. If I remove the gas cap I hear something coming from the gas tank I'm not sure if it's pressure or vacuum.

[valfam]

Hello JFP my friend has replaced the gas cap already, I agree with you about using the right part but what can you tell someone that says its the same and insist in using it. Do you know of a way to test each hose and valve? Also what about the pressure or vacuum I hear when I open the gas cap should that not mean that the system is closed and no leaks.

[JFP in PA]

P0445 is the code for a short to ground on the EVAP canister purge valve, and more often than not is a wiring problem, but can also be DME related. You need to start by checking the wiring to the purge valve to make sure the harness has not chaffed and shorted. My previous and now deleted response was for the wrong code.

[valfam]

Thanks I guess next time he has time to bring the car over and I have time to spend in it I will look at the wiring.

thanks for your help.

[Ahsai]

I don't think it is. I'm not sure. I have not heard it like the old one. Why do you ask?

Let me add one more thing. If I remove the gas cap I hear something coming from the gas tank I'm not sure if it's pressure or vacuum.

I asked because if it's clicking, at least there's power supplied meaning the circuit is probably fine. If it's not even clicking, either the part is not correct or it's not working, or there is simply no power to it. +1 on using genuine factory part or at least OEM part. Evap diagnostic itself is tricky enough that you don't really need another variable to deal with.

You can remove the connection and test the two pins (one pin should have ~14v +ve from the battery when engine is running. The DME supplies ground pulse to the other pin to activate the valve). You can use an LED in series with a resistor (say 500 ohm) to test the two pins. If the LED is blinking, at least you know there's power and DME control. Note LED has polarity though so you need to connect it with the right polarity.

To test the valves, just use a 9v battery to supply power to it. They should click when power is applied. The valve should be closed when no power is applied and open when power is applied. You can test that functionality as well even though the code is electrical in nature like JFP said.

Edited December 19, 2013 by Ahsai

[Ronnie38]

Also check for a kinked hose, I had that problem after is replaced the evp valve.

The comment on gas at 75% was that while filling the tank. if it is a C4 turn the gas nozzle upside down and it will fill ok.

[valfam]

thanks for all the help. Now I have to work on my 996. I'm replacing both window regulators.

[valfam]

You can remove the connection and test the two pins (one pin should have ~14v +ve from the battery when engine is running. The DME supplies ground pulse to the other pin to activate the valve). You can use an LED in series with a resistor (say 500 ohm) to test the two pins. If the LED is blinking, at least you know there's power and DME control. Note LED has polarity though so you need to connect it with the right polarity.

i have been working on the car today and as you said I have power on one leg (red blue wire) I see 13.7 volts so I know that is good. I ran 12 volt power to the valve and I hear and see it move so Im guessing its working. with your idea I think I can use a noid light set to see if I see power pulse on it. I just need to buy a new set Amazon here I come. I ran 12 volt power to the purge valve in the back and as soon as i give it power the engine shuts off. is this normal?

Now if someone can get me a wiring diagram so I can test at the dme and see if I have a short or a bad DME.

Edited February 22, 2014 by valfam

[Ahsai]

You can remove the connection and test the two pins (one pin should have ~14v +ve from the battery when engine is running. The DME supplies ground pulse to the other pin to activate the valve). You can use an LED in series with a resistor (say 500 ohm) to test the two pins. If the LED is blinking, at least you know there's power and DME control. Note LED has polarity though so you need to connect it with the right polarity.

i have been working on the car today and as you said I have power on one leg (red blue wire) I see 13.7 volts so I know that is good. I ran 12 volt power to the valve and I hear and see it move so Im guessing its working. with your idea I think I can use a noid light set to see if I see power pulse on it. I just need to buy a new set Amazon here I come. I ran 12 volt power to the purge valve in the back and as soon as i give it power the engine shuts off. is this normal?

Now if someone can get me a wiring diagram so I can test at the dme and see if I have a short or a bad DME.

Sounds like you lost the DME control side (violet wire either stuck to +ve or -ve). The valveis at the bottom right of the diagram below. See "Valve tank venting". The ground side is connected to pin 61 on the DME and pin 9 on the X59/1 engine harness connector. The engine died when you activated the valve with a 100% duty cycle (continuous power to the valve) is probably because of too much fuel (vapor) got sucked into the engine beyond what the DME can compensate for.

I think using LED with a resistor is safer than a noid light which is designed to test higher current output like fuel injectors. I think this valve is only using very low current so you MAY overload the DME by using a noid light to replace the valve.