I don't have anything to add here, but the best guy on this forum is helping you. CCKen. I'll follow this and hope that you track down the root cause. Best of luck!

 

Went to work today and it drove just fine, at first. The rpms started jumping and falling. No CEL. Pulled into the gas station to fill the tank and as soon as i pulled up to the pump the CEL came on. Drove to work with the CEL on. Parked it and went thru the gears to check the transmission fluid. Its good.


So i leave it sit and come back out for lunch and check codes using the key...12, 66, 45, 55. I grabbed the scanner before i left the house just in case, so i hook it up and it pops out a P1698 and P1694 along with the P0700. On the way home the CEL was on as soon as the engine was started. Drove home just fine. I googled those codes and P1698 and P1694 tend to follow one another. I think it was on Jeepsunlimited i found it? The poster had both, along with P0700. The poster replaced the CPS and all was well. If it is the CPS causing my issues i am covered as i bought a Mopar CPS a couple months, just in case. I bought a Mopar cam sensor along with it, and apparently need a new distributor as the bearing is shot. The shaft wiggles. I just ordered a new distributor.


What puzzles me more than anything right now is that once i got home and checked codes using the key, P0700 was no longer present. Just the other two. And my transmission jerks when i put it in drive. Not sure if its in the rear end, transfer case, or the transmission. Its not the ujoints as those are good and tight. Possibly the transfer case but i will save that for another thread as this one is for codes only. Carry on.

 

Thanks. If it werent for my bad luck i would have no luck at all lol. CCKen is awesome. I love his troubleshooting posts. Better than the FSM imo.

 

It would appear as though you have an intermittent TCM/PCM communication fault. It could be wiring chafing to ground or open.


P1698 is no CCD bus messages from the TCM for 10 seconds - two trips required, and P1694 is no CCD bus messages, or invalid bus messages received from the PCM for 20 seconds - attributed to the TCM.


In that you have transmission shifting problems and not starting or engine performance issues I don't see where the CPS could be at fault (but I could be wrong).


Because this is an intermittent issue I would recommend (again-see post 14) that you inspect the wiring in the engine bay for chafing through the looms to the wiring within. Pay close attention to the wiring harness that goes from the ground studs at the ignition coil (G101) along the way behind the distributor and up to the main harness. Inspect the harness that goes from the connectors at the trans dipstick down to the transmission.


Using your scanner, delete the codes. Have a helper sit in the driver's seat watching the instrument cluster. Turn the key to RUN/ON. Wiggle all the wiring harnesses in the engine bay. See if the helper sees the CEL come on at any point. Note the time frames for triggering the DTC's (10 seconds/20 seconds). In that it takes two trips for P1698 to set, it may be P1694 that's causing the fault as soon as you turn the key to run.


Statically, your TCM input reading seem to look okay, except I didn't see where you checked the resistance of the transmission output speed sensor (Cav 4), it should read open/infinity. If, by wiggling the wire harnesses you get the CEL to trigger, read the inputs again.

 

CAV 4 to 24: O.L.


I did not mess with the speed sensor wiring yet, but i have been checking the other harnesses next to the distributor including the large bundle near the engine mount for the last hour and so far, so good. No breaks, no nicks or chaffing. Nothing pinched. It would appear as tho someone was already in there as most of the factory tape (that cloth stuff) had already been sliced open, but the wiring was ok. I also disconnected every connector but one and they were all surprisingly clean. The only one i did not check was the battery temp sensor as the tab said no.


The connection at the alternator will need a little love at some point. There is minor corrosion on the B+ terminal but barely visible, even with a flashlight shoved in there. But it is there. I plan on replacing thebattery cables anyway so i am not overly concerned just yet.


I disconnected the transmission harness connectors up top and both are clean. The NSS had been replaced a couple months ago and the connector was cleaned then, but i doublechecked it anyway. Still clean.


The TCM harness is also on my list. As is checking the PCM harness between it and the TCM, but my back needs a timeout.


Btw, you are awesome! Many thanks.

 

I took care of the battery terminal clamps as they were those temporary deals. Voltage made it thru them just fine as is, but added eyelets to make them better. Voltage read a tad higher at 12.62 afterwards. Figured i better add that as part of the troubleshooting. Every little bit helps.

While i was wrapping up a family member stopped over so i had them put the key to RUN while i wiggled the speed sensor wiring next to the transfer case. It may have been coincidence but the CEL came on right after, maybe 1 or 2 seconds. All the scanner gave me was the P1698, no P1694 and no P0700. But then i remembered the TCM was disconnected so i reconnected that and cleared the code and had them put the key to RUN again, without touching the wiring. The CEL came back, with the only code being P1698 again. It doesnt appear to be an issue with the speed sensor or the wiring if the same code popped up with and without messing with it. Cleared the codes yet again and this time had them start the engine. The only code to pop up was P1698. They said the light came on as soon as the engine started. For now, it likes that particular code. I dont think i have seen the last of the other two yet, however. i keep being told to take it a dealer, which is still an option.

And whatever that clunk was appears to be gone. While i was underneath i pulled on the transfer case to crawl under there and heard a faint thud form something. Like something settled. Shifting into drive is silent again. Whatever, im happy with it.


Back to that code. I am thinking checking the resistance at each sensor might be best. Yes? There isnt much left.


Edit: After searching thru posts concerning P1698 i found mention of pulling the cluster and cleaning the plugs. Never thought of that, i will have to try it.

 

I have not messed with the cluster yet, but it is still on the list. What i am curious about now is that large white connector just behind and above the DLC. It is the instrument panel to body connector according to the FSM (C201). I see a bolt on the side. Is that the only thing holding it together? Would that be worth checking as well?

 

If your instrument cluster is working okay I wouldn't mess with it.


The connector(s) by the DLC are C100 and C200. C201 is more in the center of the dash. You could put a wrench on the bolt to see if it's tight but that's about it.


You may want to locate a replacement TCM. Your TCM catalog part number is 56027951. Check the number on your TCM to see if it matches. The '97 TCM is a one of a kind. "96 won't work nor will a '98-'01 work.


Dealer TCM is $800 (LOL)

 

Looks like i will have to dig deeper into this thing. Two TCMs in a row being bad, even used, warrants further diagnosis. I have already been told to take it to a dealer but i am going over EVERYTHING again first. $800 is far too many paychecks right now. Thats almost an entire months worth.

Yesterday i tried the old TCM on the way to work and the CEL came on immediately. I did not clear it the day before so it was likely still set from that. The light was on all the way to work and drove fine for most of the trip, but then the rpms acted up again, going up and down, and hanging. Took my foot off the gas it would hold steady, sometimes drop and pick back up. At one point the rpms dropped (slowly) as if i let off the gas, and picked back up on its own. No bucking and no jerking. Checked it with a scanner and all i got was a P1698 again, nothing else. Other than one slight hiccup in rpm on the way home it was ok. If you blinked you would have missed it, one of them deals.

This morning i checked again. Put the key in RUN and the CEL was on. Hooked up the scanner and at some point while it was communicating, the light went off. I just looked up and no light. But, the P1698 was still there. It seems to like that particular code at the moment. I have seen quite a few forums and threads pointing fingers at the CPS. Since i already have one, it cant hurt to try. Maybe i will get lucky.

Annoying as this is, i refuse to give up. I can be a stubborn mule.

 

Did you try wiggling/reposioning wiring harnesses to see if it had any effect? Sure sounds like an intermittent fault.

 

Sure did. I did not mess with the PCM however. With the engine running i pushed on the cluster at each corner, in the center, top of the dash, and around the cluster. Nothing happened so i took it off the list.

Drove to work today and the CEL was off the entire time, but it did act up, same as before. Took the scanner with me and the P1698 was still there...but no CEL. The scanner is an Actron CP9670. Found a Charging System test (forget the actual name) on it and it said DLC voltage was 11.2v (key in RUN). Started the engine and shut it off, repeated the test. DLC voltage was up a tiny bit at 11.8v (key in RUN). Shouldnt it show battery voltage? My multimeter says 12.59v, but that was at the battery without the key.

During lunch i swapped the Mopar TPS (not even 100 miles on it yet) with the one that was on it when i bought it (CTS brand of unknown mileage), just to see what happens. The CEL was off all the way home, and drove just fine, but that was just one trip. Knock on wood.

 

Its acting up again, but no CEL. The only code in there is p1698. I am running out of stuff to check and i am just sick of dealing with it so its going to the dealer. I cant take it anymore. I give up.

 

Started it up today, no CEL. Checked for codes...no codes other than 12 and 55, and nothing on the scanner. Where did the P1698 go??? So i left it run a good 5 minutes and wiggled all the harnesses and connectors i could find, again. No CEL, no P1698. I went all Yosemite Sam for a second. This Jeep is making no sense.


As frustrated as i am i did a little more googling and it would seem that ANYTHING connected to the bus could possibly set a P1698 as it saps power from the rest of it, be it the RKE, overhead console, brake light circuit, etc.. I immediately thought of my drivers door lock switch as it has not worked properly since i bought this thing. The mirror controls do not light up unless pressed at a certain spot around the buttons, only to go out again in a couple seconds, will usually come on in RUN, but go off again, and 9 times out of 10 the front passenger side window doesnt work from the driver side. Probably needs resoldered. Any relevance to P1698?


If that 'could' do it, a couple days ago when i turned the radio on (key was on accessory), there was no sound. not a single station had sound. Turned the radio off and back on, twice, before the sound came back.


I am willing to give this another shot before i take it to the dealer, provided the code comes back. One last hurrah, if you will. Any leads at all right now would be most welcome.

 

You're probably exhausted from all the BS, but do one last thing.


Gain full access to your Junction block and remove connector C4 (may a few others) and look for green corrosion living in the connector. If there is, remove the Entire JB and look on the back for corrosion.


This wouldn't be a first for XJ's.

 

This update is long overdue and i apologize for that, but i had put it on the back burner for other things. Between my last post and this one, the CEL has not come back. It did today, on the way home from just passing inspection, so atleast thats done.

I have not tested anything since last post as it did not act up, and no codes stored. I did disconnect a couple connectors and reconnected them. Aside from that, i have done nothing. It drove just fine the entire time.

However, just last week it felt like a split second miss or loss of fuel on the way to work (3-4 mile drive). Just once. No CEL and no noticeable loss of power. It drove just fine on the way home, 7 hours later. It did it again two days later on the way to work. Just once. Again, no CEL. No codes stored for either occurance, and did not take note if the tach dropped. And on the way home 7 hours later, it drove just fine again.
Now on to today.

On the way to get inspected today it did it again, just once for a split second, and no CEL. Not as much as before, but it did it. It made it to inspection and passed. On the way home it acted up again, just as briefly, with no CEL. As i drove into town i got a CEL. There was no miss or whatever it was (i still dont know), and there was a noticeable loss of power. I doubt it was a miss as the CEL was solid.
So i get home and grab the scanner. I was expecting a P0700 again, but no. This time it gave me a p1698. Curious as to what the computer was actually seeing, i tried the scanners View Data. This is what it gave me. Key on engine off. Does any of this mean anything?
ABSLT TPS % ($18) 0.4
ABSLT TPS % ($D1) 14.9
Coolant 210
IAT 167 (it jumped to 174 a couple seconds later)
MAP 29.2
o2SV11 1.000
o2SV12 1.000
Everything else was zero or N/A

The coolant and IAT readings should match, should they not? A couple degrees off i can see, but those readings are not that close in my book. Cause for concern?

After that i checked the Feeze Frame Data as i have been told this is what caused the problem (yes or no?). Key on engine off. Again, does this mean anything?
Trouble Code P1698
Fuel 1 CLSD
Fuel 2 N/A
Calc load 8.2
Coolant 194
ST FTRM 4.7
LT FTRM 3.8
MAP 12.1
ENG Speed 1216
VEH SPEED 26

As i am still new to OBD2, i have no idea what most of that stuff even means or what it should be, or if it can be ignored. I have all the factory service manuals and most of the sensors should they ever need replaced, but for now i am simply curious about what the scanner is showing me. Is it hinting at anything?


One other thing that may or not be cause for concern. As i turned the key to leave the inspection station, the engine would not start. It cranked slow like the battery was low. Tried again, same thing. Third time it started, just as i was about the try the gas pedal to see if that had any affect. I do not know if this played a part in getting a P1698, but there it is. It has been quite hot lately so perhaps that is becoming an issue as well?