99 M6 with 41K miles.
the Check Engine Light came on... had it checked:
code: P0452.
Definition: Fuel tank pressure sensor condition.
Explanation: The evaporative emission system sealed condition is monitored by the sensor.
Probable cause: 1. Fuel tank pressure sensor defective.
2. Check connector and wiring.
3. Check hoses and fittings.

I hoped it was the gas cap, so I went ahead and replaced it, which didn't fix it.

has anyone had this code?
what has fixed it?
how easy are the fixes?
thanks.

 

Did you clear the code after replacing the tank cap and see if the code came back?

 

sorry, I guess I should have mentioned that...
I disconnected the battery for a few minutes...
I assume this clears the codes... does it?
do I need to disconnect for longer?
or is there some other method to clear the codes?

 

Disconnecting your battery won't clear the codes. Pull your codes from the cars DIC and hold down the reset button while viewing them to clear all codes within the the module you are viewing...

 

how do I pull the codes from the DIC?
I havent used this part of the DIC before.

 

The short version is:
Push and hold the Options Button, then push the Fuel Button 4 times within 5 seconds. The system will automatically go through the systems, displaying codes. When its done you can use the Options button to manually go through them and the button above to go back down through them. The Reset button will clear each individual code as needed. E/M to exit.

 

OK, I followed the instructions provided by dgrant... (thanks)
there were a few codes which cleared fine, and have not returned,
but the P0452 code will not clear... even when I press the reset button...
it reads: 10-PCM P0452 C

I started the car up and the check engine light was off for about 2 seconds,
then it came on.
I shut the car off, removed the key, then restarted it and the light was on immediately.

so I guess we are back to my original question(s):
has anyone had this code?
what has fixed it?
how easy are the fixes?

Thanks...

 

I just replaced the cap yesterday...
when I got the code from AutoZone I hoped it was the gas cap as well
unfortunately that didn't fix it...
what's next?

 

OK, I was able to have a mechanic check the code issue... but when he ran the code: P0452, he said he could not find a proceedure for checking the system... he said normally when you look up the code it will give you diagnosis recommendations: check gas cap, check wiring, check fittigs, etc....
but he claimed those proceedures were not there....
does anyone know anything about the P0452 code? I would like to avoid taking it to the dealer if I can, but I need someone to tell me what I need to diagnose the problem (the code cannot be cleared, and the gas cap is new)... please help

 

All codes can be cleared,,,they might come back,,,but they can always be cleared. Be patient! Learn about your car. I have had mine for years and learn something everyday because I try to learn. The moron who said he could not find a procedure was either ignorant or lying.

The DIC code list only tells you what is not right,,,not how to fix it.

There are many threads on how to check and clear codes on the C5 Tech section. Go find them and report back. We will all help,,,right Guys?

 

On mine it was the evap canister.

It had a crack in the nipple and would not hold vacuum.

You could suck on one side and it was fine, the other side had a leak.

 

OP: Since you've eliminated the gas cap as a possible cause, try this next. Go out to your car and pop off the plastic fuel rail cover on the drivers side. You'll see a plastic ribbed line running along the side of the valve covers by the coil packs. That's your evap line. Toward the front of that line there'll be a small green cap (might be discolored tan or brown), make sure it's screwed on tight. I have seen this issue on a couple of C5's. Mine included. Also, inspect that line for breaks. It is very brittle and easy to crack if handled roughly.

Btw, if you are viewing a code in the DIC holding the reset button down will clear all codes within the module (PCM, tcs, etc). If the code comes back immediately it means your car is still detecting an issue. Clear all of your codes then post all of the codes that return after driving for a short while. That will ensure that you are only trying to solve current issues and not chasing past ones. Have you cleared this code since replacing your gas cap to see if it comes back?

 

when I hold the resset button using the DIC (after replacing the gas cap), it beeps and then says 1 code (10-PCM P0452)...
unlike a couple of other codes I HAD, which when I hit the reset button it said no codes afterwards...
thankfully after driving the car, there are no other codes... just the P0452.
I will try checking the EVAP as CDK recommended, then I can check the EVAP canister as heavymetals mentioned... (thanks to both)

to respond to silverbullet: I am also learning a lot, mainly due to all of your help.
I tried to look for a post on the P0452 code, but I couldn't find one...
the mechanic was looking for the info on how to dignose the problem using a diagnosis tool, not the DIC. (I am not sure why he can't find anything)
Autozone's diagnosis tool even provided some diagnosis:
code: P0452.
Definition: Fuel tank pressure sensor condition.
Explanation: The evaporative emission system sealed condition is monitored by the sensor.
Probable cause: 1. Fuel tank pressure sensor defective.
2. Check connector and wiring.
3. Check hoses and fittings.

If anyone knows of a previous post that would have info on the P0452 code, please let me know... otherwise I will start with the EVAP...
thanks again

 

As cdkcorvette7 suggested about the "ribbed" line, also look at the other end of it where it connects to a metal line on the firewall. Make sure it's still connected there as well. Mine came off once.

 

Diagnostic procedure.

http://www.ls2.com/boggs/dtcs/DTC%20P0452.htm

 

Thanks cdkcorvette7 for this info.

I am getting the same code. Can someone tell me if the assembly with the green cap and corrugated tube should be loose? I can twist the cap section and tube as one piece very easily. This is the section with a white clip piece at each end. I'm not sure if it's broken or if it's designed that way. Thanks in advance.