I've been having multiple '43' codes off and on in my '97 TJ/4.0L/5-speed for the last two years. Usually three 43 codes at once... as in 12 43 43 43 55. No guesses please, have you found a FIX for the three 43 codes? Here's what's been replaced or done... partially with the help of Jeep engineering who is also curious what the problem is:

New spark plugs, ignition wires, distributor cap, rotor, six injectors, ECU (engine computer), both 02 sensors, reset the computer, cleaned and reseated every electrical connection in the engine compartment. No other codes are appearing. Jeep engineering (yes the guys in Detroit) are scratching their heads on this one. Please only reply if you have had the multiple '43' codes and have found the actual CURE.

By the way... doing any of the above usually makes the 43 codes go away for about a month, but they always return. The last item I replaced was the ECU and the 43 codes went away for several months, only to return this afternoon. Grrrr :mad:

Please EMAIL me at jerrypb@cox.net ONLY if you know the precise fix, we've had a thousand suggestions from those that have not had the 43 codes, all essentially what we've done already. Jeep engineering suggests I try replacing the clock spring inside the steering wheel then the main engine wiring harness... afterall, the easy stuff has already been eliminated.

So once again, please, we've done all the stuff that comes to mind, we're only looking for that not-so-apparent fix we haven't tried yet. Thanks in adance!

which code is that?

I had on my 2000 a faulty O2 sensor. At first they kept telling me it was my gas cap not on right. Whatever. I replced that and the issue went away. Anyway you have replaced your's already.

Originally posted by JEEPRZ
which code is that?

Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders 1 thru 6. (4 and 6 cyls.)

I used to get the code 43 occasionally in my 97 XJ. It was usually accompanied by a rough idle, and I mean JUST at idle. You could barely touch the accelerator and it would run fine. It took me a while to notice that it would start after I accelerated really hard, like when I passed someone. Well, that's how I make it go away too. Now, anytime I start to get a rough idle (every couple of months I guess) I just floor it and run it through the gears, and it goes away. Works every time. No more rough idle, no more code 43. I don't know what in the hell causes it, and other than that it runs great. WEIRD, very WEIRD. Maybe you can pass that along to the Jeep guys, as I asked a dealer about it and they were clueless.

ok.... nowwwww.... here is a dumb thoughts.....

putting it all together... Could... something (another sensor?, bad gas in your area... etc) be causing ur rig to run rich or something that is causing carbon building up or something simular. Sooooo then that would explain the points of Nivloc and explain your issues possibly.

Try some gas addidive/ injecter cleaner, and after a tank or two with it cleaning see if the 43 goes away.

Hell maybe its just bad gas in your area.

Funny you should mention bad gas...

My Check engine light trips after I fill up at certain stations. Then it goes away when empty. If you ever come to oregon, I can tell you where and where not to go :D

I had code 43 for a while too. I ended up cleaning all my connections and grounds, replaced the plugs, wires, 02 sensor and it went away.

JM

Originally posted by JMyerz
Funny you should mention bad gas...

My Check engine light trips after I fill up at certain stations. Then it goes away when empty. If you ever come to oregon, I can tell you where and where not to go :D

I had code 43 for a while too. I ended up cleaning all my connections and grounds, replaced the plugs, wires, 02 sensor and it went away.

JM

hmmmmm ok... Jerry... After trying better fuels (and cleaning the motor out etc. then try the electrical route again.

Hows the salt content in your area..hell or even polution. maybe the above issue brought up by JM is the problem. Clean the all the elec. components up. If the 43 goes away;, then Put dielectirc grease on everything like you intend to do some major deep water fordging. Then see how long it takes the 43 to come back.

Is your '97 TJ 4.0l an automatic? It matters because of an updated crank angle sensor(adjustable). This is from a tsb #18-14-97 rev.A The tsb states the misfire will occur between 2500 and 3000 rpm. and set a code.

There are a few tsb's that might relate. Most of them are for re-flashing the pcm to a newer part number. I assume that was already done because of the statement about the pcm replacement. If you could get the pcm part number I could tell you if it has been done. Don't just read the number from the pcm, but look for a dealer attached label to both the hood and the pcm with a revised part number with the associated authorization (tsb#) This info will be helpful.

I have come across the clock spring issue before. It created a problem because of the cruise control switch shorting down to the O2 sensor line (cruise control is controlled by the JTEC controller)and setting a code for O2 values always high.

Other helpful tidbits I came across is with the use of "high Drivability Index" fuels. You should run only regular or mid grade fuels in your 4.0. This will play havioc with your leak dection pump system, and set false codes.

Pulling codes with the key on and off isn't a real good way to identify problems. Having an experianced dealer tech use the DRB will tell you much more. 1 trip faults, reading freeze frames when the problem occured, looking at short and long term adaptives, the drivability index, mis-fire counters, enumerator factor, purge values from learn cells, etc. I think you might want to try a different dealer if you continue to get poor results where you are dealing. There are some pretty sharp techs at Dodge dealers also, and have the same access to the newest data a bulletins.

Originally posted by dorfs
............

Other helpful tidbits I came across is with the use of "high Drivability Index" fuels. You should run only regular or mid grade fuels in your 4.0. This will play havioc with your leak dection pump system, and set false codes..........


Hmmmm I just took a long trip and thought I would use just High Grade fuel to clean the injectors. It was total 10 hours of driving. Oh way home (9th hour or so) my check engine light came on.

Error code 14 and 12 i think it was. MAP issues. Now it get put put put puts...... on deseleration too.

Did High test fuel mess up things with sensors and cause misstimming by the computer?

Originally posted by JMyerz
Funny you should mention bad gas...

My Check engine light trips after I fill up at certain stations. Then it goes away when empty. If you ever come to oregon, I can tell you where and where not to go :D

I had code 43 for a while too. I ended up cleaning all my connections and grounds, replaced the plugs, wires, 02 sensor and it went away.

JM

You probably noticed that after that day we went wheelin' huh? Yeah, I pissed in your tank, that was the problem. :flipoff2: :D