Ignition sequence, 12 and 55 on mileage

Hey guys. Accidentally stumbled upon this... I have to "prime" my vehicle for cold starts, includes turning the key to ON then OFF. Repeat that 2 more times usually.

My CEL came on the other night while driving. Havent got it scanned yet. The start after the CEL came on, I did the prime, but I waited a few more seconds before cranking, and my CEL started blinking, and the mileage read-out went blank, displayed 12 then went out. then displayed 55 then went out, then the mileage came back on. Any one know what this means?

My friend said I probably hit some ignition sequence that made it display the fault codes for the CEL being on. I looked up 1255, and couldn't find anything relevant. Im about to head to Autozone for a scan. Im assuming O2 exhaust sensor, as that has tripped the CEL before. Ill post back. Thanks.

4WDlifeform said:

My friend said I probably hit some ignition sequence that made it display the fault codes for the CEL being on. I looked up 1255, and couldn't find anything relevant. Im about to head to Autozone for a scan. Im assuming O2 exhaust sensor, as that has tripped the CEL before. Ill post back. Thanks.

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That's what you did. You got 2 codes. 12 & 55. 12 means you've disconnected your battery recently (like within the last 50 start cycles). 55 means end of codes. Any real issues would typically display other codes in between these 2.

I need to make a correction. Just tried this again, and got 12, 21, 55. Where can I find the meaning of these numbers?

Also, just scanned OBD2. its an O2 sensor on the intake I guess? I forget the code, I think it was something like P0231... looking into it now.

Found this on Jeep Forum:

http://www.jeepforum.com/forum/f12/self-diagnostic-codes-retrieval-mysterious-meaning-677141/

Pretty neat little system! So, the 21 matches the P-code I got for the O2 sensor. Now got to figure out how to fix it. Hope this becomes helpful to someone else.

Check this out: http://www.geocities.com/JeepI6Power/obd2.html

What is the production date of your 97?

I would start with checking the relay/fuse for the oxygen heater.

The "key click" codes are remnants from pre-'96 OBDI and are not as accurate as pulling OBDII codes using a real scanner.

P0231 means Fuel Pump Secondary Circuit Low. So you either have recalled the wrong code or the issue has nothing to do with your O2 sensor. Go back, pull the code with a proper scanner and post.

Saudade said:

The "key click" codes are remnants from pre-'96 OBDI and are not as accurate as pulling OBDII codes using a real scanner.

P0231 means Fuel Pump Secondary Circuit Low. So you either have recalled the wrong code or the issue has nothing to do with your O2 sensor. Go back, pull the code with a proper scanner and post.

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P0231 is not my code, that is my fault again... I do not recall the P-code, but I was certain that the scanner said 02 sensor on intake. Im going to try to locate the sensor, and see if cleaning it helps any.

Actron makes a few code readers that can also clear codes, some can even be updated in the future for newer vehicles. Do a search on eBay/Amazon.com for good prices but they are cheap:

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=0T751N95XSNAY65KNVKP