Can't pass safety inspection - P0447

SonicVQ

This is a good example of why it's import find Nissan's definition of the code:
P0447 - An improper voltage signal is sent to ECM through EVAP canister vent control valve.

It is not your gas cap.

It looks to be the canister vent control valve or wiring.
This is located in the charcoal canister at the back of the vehicle.

Find and use the FSM to troubleshoot. Most parts are easy to access.
Good luck!

Ghostvette

That is correct, however, the vent control valve 'circuit' includes the gas cap. IIRC, the first step in the FSM for that code is to check the gas cap. Part of the problem is that the OP didn't give us the mileage on the car, plus Nissan sent out recall letters about that canister and that it could be damaged due to over-filling of the gas tank. The more you know.....

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

SonicVQ

With all due respect:
The fault is an electrical issue (An improper VOLTAGE signal is sent to ECM through EVAP canister vent control valve.), so the gas cap has nothing to do with this fault.

The ECU monitors the voltage and current of its inputs and outputs to verify they are functioning properly.

On the 350z/370z (and G35/37) the vent value is a common failure. This is due to the valve being open all the time, except when the OBD evaporations monitor runs.

This allows dirt and water to find its way in and prevent the solenoid valve from make a 100% seal.

Ghostvette

The important part is that OP needs the FSM and needs to follow the troubleshooting steps outlined there. What he may find is multiple problems, a gas tank that has been over-filled, damaging the valve, causing erroneous voltage to be sent to the ECU. He could also find a damaged gas cap. Hell, he might even find a mouse or squirrel has chewed through a wire...

Access to a CONSULT system or a very good scanner would help diagnose the problem. EVAP system faults are generally a pain in the backside to troubleshoot and resolve. Between vacuum lines, sensors, valves and wires, it's not an easy fix.

I suggested gas cap because of the large number of failures I'd see on non-Nissan cars; as repairs go, it's relatively inexpensive. OP didn't give us year and mileage, so some presumptions have to made. If he bought an 09 or 10, it's entirely possible the cap has been damaged at some point, which will cause some odd fault codes, including P0447. Just an observation from many years of working on cars and watching the complexity evolve... You almost need 10k in electronic test equipment to troubleshoot cars any more.

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

SonicVQ

Agreed, if the OP wants to fix it, the easist way is to follow the steps in the FSM.

As for the gas cap or broken line, that would cause a different code. A P0442 EVAP small leak detected.

EVAP codes are not difficult to troubleshoot. In this example, I would use a 12 volt battery and connect it to the vent valve solenoid and see if it clicks.

If it does, I would then blow in one port, energize the solenoid via battery and see if the port closes.

I have successfully used the above many times to resolve EVAP issues without special tools or a smoke machine.

Cars are easier than ever to repair, you just need to understand the OBD system. For example if you have a P0442 code, you can use the mode $06 of any good $15 OBD app (like OBD Fusion) to find out how large the hole is by looking at the test results.

This is my favourite Youtube site that explains OBD functions mostly on a VQ37VHR:
https://www.youtube.com/obd4everyone