Error Codes

[esfd455]

My check engine light came on while driving today. I have a 1994 JGC 318 V-8 all time 4wd. I ran the codes with the ignition key trick. I have a 12, 21 and 55. The 12 was b/c I just changed the battery about one week ago. It means battery disconnected. The 55 is the end of codes. But the 21 means that the O2 sensor voltage has not changed. My question is where is it and do I have to change it? Does that mean its bad. after checking the codes the CHECK ENGINE LIGHT went off and has not come back on. I checked the codes and its still listed or blinks the code for the 12, 21 and 55. The JGC still runs great with no problems. Any suggestions?

Thanks,

FF/EMT Gary
New York

[Bob D.]

As long as the light stays off you should be OK. After a certain number of good start up and run cycles, the check engine light turns off.
The other codes error code/s may have been there for awhile. You will have to use a scan tool to erase the codes.

[esfd455]

Originally Posted by Bob D.

As long as the light stays off you should be OK. After a certain number of good start up and run cycles, the check engine light turns off.
The other codes error code/s may have been there for awhile. You will have to use a scan tool to erase the codes.

Thanks Bob.......Hope you had a great EASTER.......The light is still off and has not come back on......Thanks again.

FF/EMT Gary
NEW YORK

[taxman9]

Hello, my check engine light came on last night while driving home. There was no change in performance or problems that I noticed. I drove the rest of the way home and the way in to work with the radio off and nothing sounded bad. How can I check to see why this was tripped? What is the ignition trick mentioined above to get the error #'s? Thanks everyone

[taxman9]

Also, I added some fuel injector cleaner to my gas (full tank) yesterday morning, could that have caused the error.

[esfd455]

You have to turn the ignition to the on but not start position with the key........When all the lights go out then turn the key to the off position then back on real fast three times.....Then leave it in the on position. The check engine light will flash a code.......The number of flashes mean the number code......Flash twice for 2 etc.....You know what I mean. Write down the two digit numbers that show up. It will flash like mine for an example.......Flash one time then pause then flash twice......That was my 12 error code.......Thena pause then flash twice then pause then once for a 21 code.......When it flashes a 55 or five flashes pause then five flashes that means the end of the error codes. Then post back here and I will tell you the error messages.......Good luck

FF/EMT Gary
New York

[taxman9]

The codes that I got were 12, 43, and 55?? Also I did this check after the check engine light had went off, it was not on when I started my car this morning, I checked the codes just now and it came back with the results above. Thanks

[esfd455]

Originally Posted by taxman9

The codes that I got were 12, 43, and 55?? Also I did this check after the check engine light had went off, it was not on when I started my car this morning, I checked the codes just now and it came back with the results above. Thanks

Error Code 12 = Direct battery input to PCM was disconnected within the last 50 key-on cycles.

Error Code 43 = Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders.

Error Code 55 = End of error codes.


Error codes can be found at :
http://www.bcchristian.com/jeeptj/tech/error_codes.htm

Hope this helps..........

FF/EMT Gary
New York

[taxman9]

Thanks for the information Gary thats an incredible help! What does this mean in english? I havent had my battery inpput to the PCM disconnected in the past 50 key on cycles, Im assuming that because I dont know where the PCM is and havent messed with it. Where is it? Also does 43 mean basically I need new plug wires?

[esfd455]

You had to have disconnected your battery on your Jeep for the 12 error code. I just changed mine out a month ago and thats what I got for an error.

As for the 43 code......?????????? Beats me. I guess you had a bad wire or plug. Maybe someone else has more info.....I am at a loss of words on that one. Sorry.......

Have a great weekend.......We are getting about 4 inches of rain this weekend.....I sure hope Long Island does not wash away....LOL. I guess we will be very busy with car accidents this weekend......

FF/EMT Gary
New York

[taxman9]

Error Code 43 = Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders.
Anyone know what this means???