Cadillac Owners Forum banner
1 - 18 of 18 Posts

· Registered
1997 Eldorado
Joined
·
637 Posts
Discussion Starter · #1 ·
okay i had pcm p1645-Evaporative Emission (EVAP) Vent Solenoid Contorl Circuit but it went to history and i deleted it. no service engine light the whole day the moment they got in the car and tested the breaks and hooked the car up to the machine i was told i failed the reason why it says is P0507 idle control system RPM higher than expected does anyone know how i can fix this to get my sticker
 

· Registered
1997 Eldorado
Joined
·
637 Posts
Discussion Starter · #4 ·
Don't go for a retest for several days after clearing the codes. You'll fail the readiness test and thus will not pass.
so wait a few days? they dude said to clear my codes come back the next day. the only thing that doesnt make sense is the whole day no current pmc codes after the guy tested my breaks(by accelerating and breaking real hard) the codes came up current. i went home took a nap 1 hour ran my codes and the p0507 went to history so i could clear it. any reason for that?
 

· Registered
1997 Eldorado
Joined
·
637 Posts
Discussion Starter · #6 ·
I don't know what to tell you there.

Do a search for readiness test. I'm surprised he told you to clear them and come back the next day. Yeah, wait several days before retesting.
im pretty good friends with all the people at the shop. i found this online

As a general rule, doing some stop-and-go driving around town at speeds up to about 30 mph followed by five to seven minutes of steady 55 mph highway speed driving will usually set most or all of the monitors. Consequently, if you’re checking an OBD II system and discover that one or more of the monitors have not run, it may be necessary to test drive the vehicle to set the remaining monitors.
 

· Administrator
2002 F55 STS, 2014 Explorer XLT, F-150
Joined
·
80,403 Posts
If you reset only the code/ABS module, you should be OK for a retest. If you reset ALL CODES, even though there may not be any current, you reset the entire logging system to a blank slate. The emissions portion of the test will not run due to not having completed the required number of "successful driving cycles". It will present the test set with a "not ready" signal, which is a fail condition. In this case, Big Brother knows when you're trying to fool him.
 

· Cadillac Technician
none
Joined
·
11,053 Posts
History codes don't matter on an emission test. If the MIL goes off and the code goes to history it will pass with a hundred codes in history. Clearing the codes will reset the flags and the car will not pass on monitors.

It is hard to tell just by looking at those photos whether they are hooked up right or not, I can't see where the hoses go, but that other thing is just a vent yes.
They used to use a device like that third one to monitor for "flow during non-purge" but that might just be the old style EVAP vent. The newer ones are more complex with ORVR and whatever else they have going on now.
 

· Cadillac Technician
none
Joined
·
11,053 Posts
It's complicated.
You need to complete a "drive cycle".
OBD needs to see several sets of criteria be met to run tests on each subsystem for emissions control.
Some of the criteria for the tests are pretty insane and depending on the way you drive may not be met for months. When each test is completed the PCM keeps track and sets "monitor" flags which indicate that each system has passed it's self tests and it is okay.
There are flags for the O2 sensors, the EVAP system, the catalyst, and some others. On older cars they don't all have to be set, but you do have to have some set.

The only way to "know" is to connect a scan tool and check the I/M flag status to see if they are all set.
If they aren't then you may not make it through the test. In VA you'd be "rejected from testing" for flags not set.
That would be no charge to you but a pain in the rear for the testing station.
 

· Registered
1997 Eldorado
Joined
·
637 Posts
Discussion Starter · #15 ·
It's complicated.
You need to complete a "drive cycle".
OBD needs to see several sets of criteria be met to run tests on each subsystem for emissions control.
Some of the criteria for the tests are pretty insane and depending on the way you drive may not be met for months. When each test is completed the PCM keeps track and sets "monitor" flags which indicate that each system has passed it's self tests and it is okay.
There are flags for the O2 sensors, the EVAP system, the catalyst, and some others. On older cars they don't all have to be set, but you do have to have some set.

The only way to "know" is to connect a scan tool and check the I/M flag status to see if they are all set.
If they aren't then you may not make it through the test. In VA you'd be "rejected from testing" for flags not set.
That would be no charge to you but a pain in the rear for the testing station.
i do mainly city driving (stop and go) but the other night for maybe 20 miles i went on the highway going at 85 the whole time. im going to see if they can check with the scan gun tomorrow at the shop these test are a pain in the ass
 

· Cadillac Technician
none
Joined
·
11,053 Posts
It's complicated.

Make sure they don't accidentally clear the codes again!
Just have them check the I/M flags and see how many are set.
Depending on where you live and the year of the car sometimes they'll let you get by without some of them set.
I'd have to look it up but I think you can pass on a '97 with 2 flags not set.
Newer ones you only get one not set.
I am not sure if they have made the most recent ones more strict as to have them all set or not.
I guess I should know, but the dyno checks all that stuff for me so I get lazy. :lol:
Good luck.
You might be okay.
 
1 - 18 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top