Tranny code question...

[joe_peters]

Code P0351 is referring to a coil fault.

That said, just read a very long thread for a ZJ 4.0 guy went through everything--multiple coils, multiple crank sensors, cam synch sensor--final result was a bad PCM for him.

 

[mickyfinn]

I think I read the same thread too and a few other similar ones over the last few weeks. I was too busy to get to the jeep yesterday, but I should have some time to dig into it today. By the looks of it, people have been looking for electrical problems in this car for some time. All of the wires coming out of the TCM, the ignition harness, and all over have been pricked for testing. It also looks like someone might have put an aftermarket remote car starter in at one point and just cut it out leaving the splices. Basically, it looks like someone's been chasing these problems for some time.

What are your thoughts on changing the PCM, as in new vs. used, or aftermarket/rebuilt vs. dealer.? I hate just throwing parts into the thing, but I'm beginning to think this may be worth it. The "tech" installed all those new parts based on a Chrysler diagnostic computer's directions, not only the TCM, NSS, and TPS, but some evap parts, ignition switch, starter, and several other seemingly random parts. He said he kept pulling those same 0700 and 0705 code, plus various other ones that would pop up. New codes, new parts... I'm getting the same thing still, with the 1899, the new 0351 code and the 0463 earlier. I'm wondering if the PCM is just going nutty. I always tend to lean toward simple first, like poor grounds or bad connections, and I think I've chased them all down (although, now that I think of it, I haven't done one near the PCM and I remember now a thread that mentioned it...)

I'll update later with what I found. Thanks again for the insight!

 

[mickyfinn]

Okay, finally got a chance to look at it. I removed the PCM and inspected terminals and connectors, didn't look too bad. There was someones old splice off one of the grounds in one of the connectors which was spliced into another ground wire from the harness which led to a ground screw on the well. The splice was soldered but poorly wrapped which led some corrosion of the wires themselves, and the well grounds were pretty corroded too. I cleaned them all, cut out the bad wire sections and re-ground everything.

Cleared the codes, went to start and crank but no start (which it has been doing pretty consistently now). It popped new codes, 0700 and 0705, and the starter would crank in all gears. I pulled the brand new NSS, inspected and it tested fine. Re-installed and adjusted with voltmeter. Car started right up, and has several times. No CEL yet, which I thought might be good given it was instantly on before I removed the NSS.

Problem though, car still starts in every gear!! At this point, I think I need to bite the bullet and switch out the PCM. Any thoughts on this? Or better, any reason anyone can think of that the NSS is working but the car will still start??

Any thoughts on used/after market PCMs?

Thanks!!

 

[joe_peters]

Hold off on the PCM. Starting in all gears is either the NSS or someone has a ground jumper to the starter relay.

That is how the NSS keeps it from cranking, it interrupts the ground to the starter relay. Hook up a volt/ohm meter to the starter relay cavity where the 30 connector of the relay goes in. Set to ohms, then try shifting through all of the gears. If the circuit is never broken (OPEN), then suspect the NSS or the harness between the starter relay socket and the NSS.

 

[lawsoncl]

There was someones old splice off one of the grounds in one of the connectors which was spliced into another ground wire from the harness which led to a ground screw on the well..... Problem though, car still starts in every gear!!

I bet if you removed that extra ground wire, it'll stop starting in every gear. I'm betting the previous owner added the ground to bypass a problematic NSS.

 

[Shorty]

I bet if you removed that extra ground wire, it'll stop starting in every gear. I'm betting the previous owner added the ground to bypass a problematic NSS.

not sure on newer (OBDll) models, but if it were constantly grounded, the ECU may be "seeing" that it's in park/neutral at all times. This might give erroneous information that could cause your trouble code, no?

 

[lawsoncl]

not sure on newer (OBDll) models, but if it were constantly grounded, the ECU may be "seeing" that it's in park/neutral at all times. This might give erroneous information that could cause your trouble code, no?

Yes I believe the Trans computer will throw an error code. Which would also explain the 0700and 0705 codes he's getting.

P0700 is set by the PCM, saying tcm has a code
P0705 is set by the TCM, which believes the NSS is faulty

 

[mickyfinn]

Hey guys, interesting take on the NSS bypass. I'll try taking that jumper out and see what happens.

I'll also check the starter relay but I'll need a tutoring there. Where is the starter relay located? And I'm guessing I'm testing the #30 socket to ground with the ohm meter. Right?

Thanks!

 

[Shorty]

I'll also check the starter relay but I'll need a tutoring there. Where is the starter relay located?not sure on newer body-- PDC, I would assume And I'm guessing I'm testing the #30 socket to ground with the ohm meter. Right? either 85 or 86 should have 12V with the key in start position, the other terminal should be grounded only in park or neutral IIRC

Thanks!

 

[mickyfinn]

Lawsoncl gets the prize! Cut the jumper wire and it now starts as it should. I cleared the codes and so far it's been through a few starts without coming on. Here's what I'm thinking~ the car did not always start in every gear since we got it back with the new NSS and TCM. The connection of the jumper wire had some serious corrosion on it so I think it was intermittently "working", allowing the NSS to function properly sometimes.

Assuming it needed the NSS and/or TCM originally and the previous owner ran the jumper to avoid the replacement, then the tranny code problems should disappear.

Now the $20,000. question, the stalling/ crank-no-start issue it's been having. That jumper wouldn't have anything to do with that, would it? Bad grounds to the PCM could cause that though, huh??? I'm hoping fixing the bad grounds from the PMC and cleaning & greasing the connectors might actually solve the stall issue as well. I'll update with whatever happens.

Once again, THANK YOU everyone! Looking forward to my chance to pay it forward!

 

[FlexdXJ]

Now the $20,000. question, the stalling/ crank-no-start issue it's been having. That jumper wouldn't have anything to do with that, would it? Bad grounds to the PCM could cause that though, huh??? I'm hoping fixing the bad grounds from the PMC and cleaning & greasing the connectors might actually solve the stall issue as well. I'll update with whatever happens.

Once again, THANK YOU everyone! Looking forward to my chance to pay it forward!

This leads me to believe you may have a crank position sensor on the Fritz. Generally, when they start to go bad it causes intermittent stalling. If the key turns and it does absolutely nothing its usually the cps. I could be wrong but that's my take on the symptoms you described.

 

[kastein]

If the key turns, the motor cranks, and it does absolutely nothing, it's USUALLY the CPS but can be a host of other issues as well.

You can check this by attaching a noid light to your injectors & ignition coil and driving... when it stalls out intermittently keep an eye on the light, if it stops flickering, you are losing whatever it's connected to at the moment.

The P0700 *should* go away as soon as the TCU realizes all is well again. If it doesn't, try clearing the codes and it should not come back.

 

[mickyfinn]

Update~ CEL has stayed off through an afternoon of errand running and codes stayed clear. I think I've seen the end of the tranny code issue.

BUT... it started stalling again after driving around for a while. It hiccupped once as I turned a corner, then I parked it for an hour or so. When I got back in I didn't get 2 mins down the road when it cut out while moving. I popped it in neutral (tried drive, NSS still working!) and it fired right up. It then proceeded to stall every minute or so until I could limp it back to my shop. I noticed in that time that that it started right up every time except for once when I had to crank it @ 10 times to get it fired. It also seemed to just cut right out, except for once when it seemed to buck and sputter for about 10 seconds as I pumped the pedal until it died.

Granted I was driving in town and didn't get too long of a stretch of higher RPM driving, but it seemed to stall more when I was cruising or slowing down and then gave it some gas, also when I was starting out a couple of lights. I did also do it under some motor load, but I noticed it more when motor was at or below 1200 rpm.

From what I read, crank sensors seem to not be too intermittent when they fail, but given the corrosion everywhere else I thought I would start with the connector and take a look at it. Hopefully get to that today. I've read about fuel pump issues, but it doesn't really feel like fuel deliverance except for that one time it sputtered.

Warm or cold, doesn't seem to matter. EGR maybe?? I'm open to suggestion! Would any of these potential issues trip different codes? I did have at one point that p0351 coil code and another time a 0463 code that I think was a voltage issue for the fuel sender (gotta admit though, didn't write that one down and was debating 0463 vs 0465 and I'm not sure what that was).

Also, should I end this thread with the tranny codes fixed now and start a new one for this issue?

Thanks!

 

[mickyfinn]

Update~ CEL has stayed off through an afternoon of errand running and codes stayed clear. I think I've seen the end of the tranny code issue.

BUT... it started stalling again after driving around for a while. It hiccupped once as I turned a corner, then I parked it for an hour or so. When I got back in I didn't get 2 mins down the road when it cut out while moving. I popped it in neutral (tried drive, NSS still working!) and it fired right up. It then proceeded to stall every minute or so until I could limp it back to my shop. I noticed in that time that that it started right up every time except for once when I had to crank it @ 10 times to get it fired. It also seemed to just cut right out, except for once when it seemed to buck and sputter for about 10 seconds as I pumped the pedal until it died.

Granted I was driving in town and didn't get too long of a stretch of higher RPM driving, but it seemed to stall more when I was cruising or slowing down and then gave it some gas, also when I was starting out a couple of lights. I did also do it under some motor load, but I noticed it more when motor was at or below 1200 rpm.

From what I read, crank sensors seem to not be too intermittent when they fail, but given the corrosion everywhere else I thought I would start with the connector and take a look at it. Hopefully get to that today. I've read about fuel pump issues, but it doesn't really feel like fuel deliverance except for that one time it sputtered.

Warm or cold, doesn't seem to matter. EGR maybe?? I'm open to suggestion! Would any of these potential issues trip different codes? I did have at one point that p0351 coil code and another time a 0463 code that I think was a voltage issue for the fuel sender (gotta admit though, didn't write that one down and was debating 0463 vs 0465 and I'm not sure what that was).

Also, should I end this thread with the tranny codes fixed now and start a new one for this issue?

Thanks!

 

[mickyfinn]

Update~ CEL has stayed off through an afternoon of errand running and codes stayed clear. I think I've seen the end of the tranny code issue.

BUT... it started stalling again after driving around for a while. It hiccupped once as I turned a corner, then I parked it for an hour or so. When I got back in I didn't get 2 mins down the road when it cut out while moving. I popped it in neutral (tried drive, NSS still working!) and it fired right up. It then proceeded to stall every minute or so until I could limp it back to my shop. I noticed in that time that that it started right up every time except for once when I had to crank it @ 10 times to get it fired. It also seemed to just cut right out, except for once when it seemed to buck and sputter for about 10 seconds as I pumped the pedal until it died.

Granted I was driving in town and didn't get too long of a stretch of higher RPM driving, but it seemed to stall more when I was cruising or slowing down and then gave it some gas, also when I was starting out a couple of lights. I did also do it under some motor load, but I noticed it more when motor was at or below 1200 rpm.

From what I read, crank sensors seem to not be too intermittent when they fail, but given the corrosion everywhere else I thought I would start with the connector and take a look at it. Hopefully get to that today. I've read about fuel pump issues, but it doesn't really feel like fuel deliverance except for that one time it sputtered.

Warm or cold, doesn't seem to matter. EGR maybe?? I'm open to suggestion! Would any of these potential issues trip different codes? I did have at one point that p0351 coil code and another time a 0463 code that I think was a voltage issue for the fuel sender (gotta admit though, didn't write that one down and was debating 0463 vs 0465 and I'm not sure what that was).

Also, should I end this thread with the tranny codes fixed now and start a new one for this issue?

Thanks!

 

[McQue]

you can try pouring cold water on the cps when it dies... that has been known to temporarily fix a cps that is heat sensitive... if it restarts right away, you know that is the problem.

If I were you, I would start a new thread for this problem.

 

[kastein]

The 463 code is the fuel level sensor, ignore it, all it affects is your gas gauge.

Unless it's the 465 code, which is an EVAP purge flow sensor fault, and I'm not sure whether the XJ even has a purge flow sensor or not.

 

[mickyfinn]

Thanks guys, I'll try and get to checking that crank sensor connection today and start another thread if some searching doesn't turn up anything that helps!

 

[lawsoncl]

Just to note, a bad CPS sensor will often not throw any trouble codes.

It's odd that it doesn't, since the PCM should be able to figure it out when it sees no signal from the crank sensor, but still sees rotation from the distributor sensor.

 

[mickyfinn]

Hopefully the final update on a laundry list of problems... After cutting out the jumper, no more tranny codes! The stalling issue came from two different problems. The first I found early, the bad wire to the stator. This last issue was not the crank sensor (although, I changed it to hedge my bets!), it was ANOTHER bad wire, this time a primary wire to the coil! I'm going on five days now with no stalling and the only code still kicking is that 0463 fuel sender voltage code (driving it around, I've noticed for the first time that the fuel gauge is all over the place). The girlfriend is going to bring it back to her "tech" friend and make him change out the sender (and I recommended the pump/filter since he's there) to make up for the huge money he wasted her. Personally, I wouldn't let him touch it, but it's a pain in the ass job and she's on a tear~ and she's REALLY scary sometimes!


This has been a real birth by fire for my first Jeep foray! A solid education, and much of it due to all the help from here! Thanks again!!