Ok guys ive been trying to figure out or find the problems with my 2000 xj 4.0 sport. Ok ive searched this thread number of times and did pretty much everything people have suggested and still no luck. I get codes p0443,p0135,p0138,p0141. Heres what i have done so far, replaced main ground wire and end from battery to block and to fender well, replaced ground from back of cyl head to fire wall and cleaned all grounds by the ecm, plus replaced positive cable from battery to starter and fuse distribution box under hood. replaced both o2 sensors, did a ecm reset, o2 sensor fuses are fine as well as both relays. all wiring from sensors into harness seem to be fine nothing broken that i can find.. ANything else am i missing??? Or any other area i need to look at?? been fightn this for about a month now, cant even drive it!!! this jeep has been the biggest pain in the a.. vehical i have ever owned, i never had so many problems in my life with a vehical as this jeep has givin me. OK it idles ok when cold until it warms up some then misfires like crazy can hardly rev it at all without it backfiring throu the intake. it also dies sometimes when idling like that. but theres times when you hit the gas and it runs like normal or if you shut it off then start it back up idles fine then with in a min or 2 does same thing..so put the gas pedal down to get it at 1500rpms & held it there would be good for maybe 30 seconds then it spits sputters then clears up for a few seconds then back to missing/spitting/sputtering.. im at a lose is the ecm junk?? I have no clue what else i can do. Please please any help would be great again.. I have a new crank sensor for it on the shelf but i dont get any codes for it so i figure the one thats in there is fine.. What else is there??? p.s. no vacuum leaks or intake leaks either. also got the tranny range selector code also and lost reverse lights, still no reverse lights after clearing all codes and doing a ecm reset. after the reset turn the key on not starting it and cel is on with just the p0443 (evap) code then the o2 sensor codes appear after it running for a couple minutes.. please help and sorry for the long post, just trying to give as much info as possible

 

P0443 (M) Evap Purge Solenoid Circuit An open or shorted condition detected in the EVAP purge solenoid control circuit.

P0135 (M) 1/1 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.

P0138 (M) 1/2 O2 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal operating range.

P0141 (M) 1/2 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.

Have you measured the actual applied voltage to the O2 Sensors and purge valve?

 

Keep in mind that the PCM completes circuits by completing the ground path. If your voltage to the sensors and valve is incorrect then clean grounds won't matter.

 

I tested the evap couple weeks ago, i know i should of wrote the the voltage but if i remember right it was 4 or 5v at the plug on the purge solenoid which doesnt seem right. I also tested the purge solenoid to see if it even clicks, i did it how people mentioned on the forum here, and it clicks with a power probe so the solenoid must be fine i take it?? Plus its just to vent gas tank vapors anyways, its it really needed? only to pass emissions right? I just want to get the thing running right so i can drive it seeing it was my daily driver. the o2 sensors, my friend has a scanner with live data, old sensors measured 1.5v upstream and .9v down stream and with jeep running no change in voltage between the 2, they stayed right where they are at.. He wont let me use the scanner so have no clue what new sensors are measuring as i just put them in today. Im going to assume same voltage as for the codes coming back up.. Is there a way of testing the wire/wires coming out of the ecm for the o2 sensors for voltage and if its even receiving a signal or ground? if so what number wire/wires (pin) is it on the ecm. my manual doesnt show my jack squat for anything like that

 

If I were you I would buy a junk yard ecm and try it. If it drew in moisture theres a really good chance that its BAD. I had that problem once before and that solved the problem.Also had one with a bad distributor bearing that did the same thing yours is doing. worth a try.

 

thats what im thinking of doing but they are a little pricey, not sure what the going rate is for them but one place that has a couple of 2000 they want 125.00 plus this was i dont have to get it programed since its the same year. Im probably going to replace the crank sensor since i have one sitting here. also just read that the ecm may not pick up on a bad cps to give the code, i dunno, if that doesnt do it then i have the original for a spare then. ALso not sure if moisture got it there hard to tell..But all this started after i replaced the pasenger side power lock/window control modgual. closed the door and the engine light came on with the codes. waited a week, then unpluged the window/lock modgual thinking somehow that was back feeding into the system but nothing changed there either.

 

mine doesnt have the distributor its got the coil pack/rail or whatever you want to call it, but going to try the crank sensor then the computer if the crank sensor doesnt fix it, this thing is a money pit my god....

 

I have a '97 but maybe the OP's 2000 is same/similar:

For codes P0135/P0141 have you checked the O2 heater fuse? My diagram shows fuse #23 is a 15A fuse in the PDC for the sensor heaters. If the fuse is blown, maybe something to do with the P0138 code did it.

With the evap purge code P0443 my diagram shows fuse #11 in the junction block in the cabin is a 20A fuse in line with the purge solenoid.

Maybe see if these fuses are blown and more importantly, what made them blow?

Once again, my info comes from a '97 FSM so your 2000 may differ a little. Not too much, I hope. For the OP, good hunting!

 

Fuses and relays are good for the 02 sensors. I never could fine a fuse for evap. my hayes manual sucks. its doesnt show any of that info for what fuse is what

 

What would cause the ecm to want to push out more volts to the 02 sensors?? 1.5v & .9v... Im guessing its not recieving a signal back or the ecm isnt completing the path with the ground, like the ecm internally failed a ground?? Is there a way of testing the ecm if its shot or not??

 

as far as the evap code, with the engine running at idle when first started....does the purge valve on the front left side of the engine compartment click on and off constantly?


Did you check to see if the O2 wires where burned or damaged where they are pined up along the side of the block behind the exhaust manifold pipes?

 

Replace that crank sensor since you have it. They don't always throw a code for it when they are about to go bad, but can cause the motor to run like crap which in turn can make some of those other codes appear.

 

You could also check the Great Lakes Subforum for CF members from around that area and ask them if they'd be willing to swap ECUs with you so you can test. I just had a quick look and saw '00 owners from Sheboygan, Plymouth, and Elkhart Lake. Just a thought.

 

ReplaceD the crank sensor and still the exact same stuff I let the repair shop right next to me look at it and they narrowed it down to the first o2 sensor. both or 2 sensors are brand new by the way. if he on plugs the first 02 sensor it runs beautiful absolutely no problems. plug it back in and within a minute it's spitting and sputtering backfiring misfiring. and now I have a transmission cold also that will not go away a constantly reappears. what do you think you could be with that first o2 sensor u unplug it and it works fine. do you think the Santa could be bad? I put some cheap ones in off of Rock auto.com called ultrapower. probably going to order the ntk brand. any other ideas?? I'm still trying to track down a good ECm I could swap out to see if mine is bad or not