Hi Monte Carlo people. I need help with my 2005 SS car.

I had a cracked Evap vacuum line to evap solenoid. An replaced the line and now i have no code now. But my ECM will not run the EVAP diagnostics. I have driven for 2 days and not let the gas go below a 1/4 thank not over 1/2 a tank about 150 miles now. The engine temp is normal also. on the dash gauge about one graduation below center. The car is a 2005 SS Monte Carlo. How can i get this to do its selftest or whats keeping it from running. Checked i have no codes or pending codes. The car is running great. No idea how to get it to do the selftest.


thank you
Scott

 

Have a fuel level that's not too full or too empty. Start the engine from fully cold. Drive around some.

If it gives you a hard time:
-Make sure the weather is reasonable. Extreme temperatures can prevent the monitor running. Adjust weather as necessary.
-Check for pending codes. Pending codes (even if not related) can stop a monitor from running.
-Turn off the AC.
-Check your driving style. Hang a pendulum from the rearview mirror. If it swings fore and aft as you drive down the road, you might be an old woman. Dampen that foot motion. This may also cure neck pain.


You may have to perform the test more than once for it to actually work, try once while the car is cold after sitting for a minimum of 6 hours, and then again repeat the procedure when the car is warm.

If you are not going in for an e test then I would just drive it for a while and see.

Hope that helps

 

I think you need to get up to around 35 - 40 mph for a steady period while doing it, you basically need the car in motion but do not allow the gas to slosh around in the tank, by not accelerating hard or braking hard.

 

I live in Santa Barbara and the weather is mild. its had 3 cold starts here and i have driven it about 150 miles by now and its still not cleared. I need to get it smogged and they will not test the car tell its set. What makes this not run the selftest or how do i make it run the test?

 

Hi Scott,
I would check it with another scanner. I'm not saying the scanner you used is bad. But it seems odd to me that the scanner is saying the evaps isn't running but your car is running fine and with no codes. Do you have a smell of fuel in the car? When you take the gas cap off do you hear a quick puff/ suck of air? Could be that your PCM is taking it's time to reset. Could be that you have a bad connection. All are worth checking out!

 

Hi JC I did that i went to a friends shop and used his scanner and also went to the smog shop and asked them too. now that 3 scanners that say no code no pending codes but evap not run. I think that 5 of the 6 on board PMC or ECM self test done less the evap. Its now had 4 cold starts and 180 miles driven on it since i fixed the cracked line and cleared the codes. Plus its running great with a smooth idle. As for the gas cap i dont think i have ever really heard it depressor when i have opened the gas cap.

 

Can you get access to a spare gas cap? just for testing purposes. May be worth a shot

Also have you tried unplugging the battery for about 30 - 40 mins. This should clear everything again, and hopefully your car will run all it's checks.

There is a detailed process in how to get the car to run all off it's internal diagnostics, and I know it was posted on the forum, as I printed it out when I was having issues with a code clearing after I fixed the part. I will see if I can find it and if so I will post the link

 

Here is a link to the General Motors Driving Cycle for the OBD 11

General Motors Driving Cycle

Hopefully it helps

 

This was going to be my suggestion also. You may need to repeat the drive cycle more than once before all diagnostics will be in the ready state.

 

Ok after looking at the time it took for my car to go from a Santa Barbara cold start it was about 45 deg in the morning to 190 deg operating temp took about 7 min. Not so long as to pitch a code but to long to start the evap selftest. So out of just trying anything i bought a new thermostat. An installed it started the car from a cold start and was up to temp in 3 min. Looked on my scan tool and the evap selftest ran. So not so sure why but its good now.

Thank you for all you help out there

Scott