Topic: Crap its Emissions time! And I need help.

[mitchh]

So My 97' Is giving me a code 12 (with the key trick) It means, direct power to pcm disconected with in the last 50 key cycles. Its been showing up that way since Feb. Im pretty sure ive started it 50 times since then. Heres the Q. Does that code affect the Obd? Will my emissions system still start and function like normal? Also I know that in some cases that disconecting the battery will "reset" any stored codes resulting in no data stored or show up as sensors "not ready" resulting in emissions failure. Here in Illinois you need to pas the smog test to renew your plates, and you cant park on the street with out valid tags or you will get ticketed and towed. And my plates need to be renewed at the end of may. Any help will be great!

[jfrabat]

So My 97' Is giving me a code 12 (with the key trick) It means, direct power to pcm disconected with in the last 50 key cycles. Its been showing up that way since Feb. Im pretty sure ive started it 50 times since then. Heres the Q. Does that code affect the Obd? Will my emissions system still start and function like normal? Also I know that in some cases that disconecting the battery will "reset" any stored codes resulting in no data stored or show up as sensors "not ready" resulting in emissions failure. Here in Illinois you need to pas the smog test to renew your plates, and you cant park on the street with out valid tags or you will get ticketed and towed. And my plates need to be renewed at the end of may. Any help will be great!

IIRC, you need the 50 cycles to pass (read about that one on Popular Mechanics or similar, about how changing your battery before the test was NOT a good idea)...  What you can do, though, is stop the engine and restart at stop lights.

[grumpygy]

Move

  No check here

[mitchh]

Only if I could move, the wife won't have any of that now. Otherwise I would be up in the Northwoods of wisconsin kayak fishing and hunting all the time! I have been trying to start the jeep five or six times when ever I do start it. How long does it need to be started for? Just till all the cluster lights go out?

[grumpygy]

Synopsis
Description:  Memory standby power recently lost
Power loss light:  Off
Limp-in mode:  None



Possible Causes
Battery or power line recently disconnected - This code is normal if the electrical system has been worked on or the battery has recently been disconnected.  It will be removed after 15 ignition switch on/off cycles.

Low system voltage, bad battery or battery terminals - If the system recently had a power drop (due to a dead battery or bad alternator), this code will appear.  If the battery terminals are bad and the engine was jumped, this code will appear.  See the Diagnosing Your Charging System page for more information.

Bad connection or wiring - Check the wiring and connections between the battery, power module, and logic module (or SMEC).  Check all fusible links and power connectors to the battery.  Clean and regrease any corroded connectors with dielectric grease and repair any shorts.



Diagnostic Method
Trigger Parameters
- Logic module receives power after previously not having power

Results If Component Fails
Fault code 12 is stored.  The logic module is basically telling you that it has lost power and will not remember any previously stored codes or engine sensor table data.  The code will be removed after 15 ignition on/off cycles and the logic module will use default values for all look-up tables as a starting point until it "learns" the attributes of the engine.

[Jeffy]

Code 12 should not have any significant bearing on anything emission-wise.  It just means the PCM's in default mode and will be learning.  Drive it around for a while before getting it tested.  The more miles the better but it shouldn't fail you unless your Jeeps already borderline to begin with.

[JohnnyO]

A new air filter and plugs, maybe new wires if they look crusty, change the oil (synthetic is better to help it pass) and run a bottle of Techron fuel system cleaner through the tank before you go.  Higher octane gas will not help it pass and in fact might make it worse.  I have used something called catalytic converter cleaner that you dump in your gas tank, pricey stuff at about $24 a bottle but cheaper than a new cat, it got my son's car to pass and got rid of the rotten egg smell too.

[mitchh]

Thanks for the info guys. I just put new plugs, wires, cap, rotor and air cleaner on. Im not worried other than that damn code 12. I took my Commander in for warranty work, than a few days later took it for emissions and it faild cause it read the battery was disconected.  Well Im going to give it a try tomorrow, Ill post back with the results. Thanks again!

[mitchh]

It PASSED!!!  Although Its a bit sluggish and will bog down/hicup when shifting from first to second I have a hard time keeping 65mph on the hwy. My mpgs are gettin kind of crappy to, about 11 city and 13. Although Im getting no codes is there a chance that the upstream 02 sensor is crapping out on me? My plugs were a little white when I changed them. I posted the same Q a while back on the jeepforum, some of you may know Jerry B. recomended a new upstream o2. I figured all you 4 banger owners would give better advice than what I get over there, the ususal Rx is sell it for a I6.
By the way its a 97 with Rough country 2.5" lift and the stock 4:11's and 5spd

[JohnnyO]

Ours crapped out a few weeks ago and wouldn't even stay running.  Had to get it towed to the shop.  Turned out to be both O2 sensors, although the CEL never came on.  Older systems (ours is a 97 also) aren't as sophisticated and won't always trigger a CEL.

[chrisfranklin]

It PASSED!!!  Although Its a bit sluggish and will bog down/hicup when shifting from first to second I have a hard time keeping 65mph on the hwy. My mpgs are gettin kind of crappy to, about 11 city and 13. Although Im getting no codes is there a chance that the upstream 02 sensor is crapping out on me? My plugs were a little white when I changed them. I posted the same Q a while back on the jeepforum, some of you may know Jerry B. recomended a new upstream o2. I figured all you 4 banger owners would give better advice than what I get over there, the ususal Rx is sell it for a I6.
By the way its a 97 with Rough country 2.5" lift and the stock 4:11's and 5spd

. 
How's your MAP Sensor?  If it's the same one that was on there when the Jeep was new in '97, the sensor may be ready for a cleaning or replacement (since a new one doesn't cost much).  I replaced mine recently and it was, in all likelihood, 17 years old.  No codes or anything, but when I replaced it and the MAP tubing and cleaned out the intake port for it, I later noticed a pronounced change in drive-ability (wasn't on-the-pedal as much, like before -- this might, correspondingly, yield better mileage) 

[mitchh]

So I just went to the auto parts store. I picked up a new upstream o2 sensor. I disconected the old one and ran it for a while. It didnt even throw a cel. So I popped in a new sensor. Ill take it out for a test drive tomorrow. Ive read that you should reset the computer after replacing the 02. What's the steps for that. Something like disconect pos batt terminal and ground it to the chassis, turn lights on and reconect.

[JohnnyO]

What's the steps for that. Something like disconect pos batt terminal and ground it to the chassis, turn lights on and reconect.

As far as I know just disconnect the battery for about 15 minutes.  But I'm more familiar with Fords.