how do you clear the codes

[mark15pa]

I replaced the MAP sensor today , but I am wondering if there is a way to clear the codes without going back to autozone to have them do it, Any help will be greatly appreciated.

[enslow]

You could disconnect the negative battery terminal for 30 minutes and that will clear the code. However, be aware that if you are going for an emissions test, you will have to drive it until the "readiness monitors" are on.

[auto trainy]

That's a new one for me ,What is a readiness monitor?

[Scrapper]

yah just take neg. cable off for about 15 to 20 mins. and then hook back up and should reset computer and should be ready to go.

[mark15pa]

I tried a bunch of different things , I tried removing the negative on battery for 30 minutes, i tried removing PCM fuse for 30 seconds, I tried something one of the moderators put on a previous post, I tried removing the positive cable, I even was told to try to turn key to on and stomp the pedal 3 times in rapid sucsession , but low and behold nothing seems to work. A fellow employee at work said he would try and remember to bring his code reader tomorrow and reset them for me , so I'm crossing my fingers, otherwise I'm just going to put a piece of blacktape over it and forget it!! I hate the idiot lights on automobiles but I guess they serve a purpose

[old_master]

Disconnecting the battery will turn off the SES light only if there are no hard faults detected by the PCM after re-connecting the battery. It will only clear pending DTC's, not history file DTC's. It will not reset the readiness monitors, misfire history or fuel trim. Most "code readers" can only read the history file DTC's, that's all. Some of the el cheapo $200 to $400 scan tools like the auto parts stores use, will access freeze frame data, clear the history files and reset the readiness monitors. It requires a high end scan tool, ($2,000 to $10,000 range) to access camshaft retard data, reset fuel trim, misfire history, and perform bidirectional procedures such as crankshaft position sensor relearn, IAC reset, and flash the PCM/VCM etc etc.

Auto trainy:

There are several systems called monitors that run their tests under certain driving conditions. Some run once per drive trip, some once per drive cycle, and some are continuous. Each monitor must run, complete, and pass its test before the vehicle is allowed to be tested for State emission levels. The technician can tell very quickly if all readiness monitors are complete. If they're not, it usually means the system was reset trying to turn off the SES light to cover up a problem. A drive cycle can be completed in about 15 minutes and force all monitors to run and complete their tests. Each monitor has a "set" of requirements that must be completed exactly to the letter, or the test will not run and/or complete. Under "normal" driving situations, it's possible for a vehicle to go 6 months and not have all of the monitors run and complete their tests. Here is a link to the GM drive cycle: http://www.obdii.com/drivecycle.html The first time you try it, don't be surprised if it takes you over an hour! It's harder than it sounds.

[polarzak]

old master....that is the BEST jPeg and comment I have seen in some time. I cannot wait for the crying to commence.

[auto trainy]

Old master,thank you for the in depth technical response,you will not hear any crying on my part because of my ignorance,your response was one of best I've had in years.