Engine Code Questions

P1694 and PO700??

Ok, I've done the search and got some idea but my situation sounds a little different than what I've read.

This has only happen to me twice and in the same situation, cruisin down the highway at a steady 70mph with the cruise on for a duration. The engine will studder and buck, then quit. I pop the auto in neutral and it restarts fine and I go along with no issues. I pull over pop the code reader on and get those two codes. Now I figure the PO700 is a tranny code and its from the bucking caused by the studdering engine, so I am not worried about that. But they don't list the P1694 code in my repair manual. But from what I've read it could be my CPS acting up or even my TPS sensor.

Hopefully, somebody out there has some experiance and will help me before I go out and spend $100 or so on sensors, chance ghosts.

Have you tried turning the key on then off then on then off then leaving it on so the check engine light blinks the a code? That code is listed in the haynes manual if you have on of those....

That would work on a pre 95, but having a 98, I get to the ODBII

From the 99 FSM

P0700 is "EATX Controller DTC Present...This SBECIII or JTEC DTC indicates that the EATX or Aisin Controller has an active fault and has illuminated the MIL via a CCD (EATX) or SCI (Aisin) message. The specific fault must be acquired from the EATX via CCD or from the Aisin via ISO-9141."

P1694 is also possibly a tranny code, "fault in companion module .... No CCD/J1850 messages received from the powertrain control module-Aisin transmission."

P1694 also can mean Bus communication failure to PCM. If it is this, it should set a malfunction indicator light, and if no light, it's presumably the tranny issue.

In other words, you might need more than the generic scan tool to figure out the source of those codes, but my first guess would be that you should check carefully for damage or poor connections, especially in the wiring between the TCM and PCM.

Thanks for the heads up Matt. I just pulled my CPS and it was dirty as hell, covered with this nice oily grime, cleaned it off and we'll see what happens. I'll take a look at the plugs for the tranny. But the thing about this situation is it doesn't rear its ugly head all the time, you can't predict when it will happen. The first time this bucking happened all I got was a P0306 code, mis-fire on cyl. 6, this time I got the two codes P0700 and P1694, but the situations and jeep reactions were both the same, bucking and the engine would quit, followed by me putting the tranny in neutral and restarting at 60 mph and then it would run fine like nothing happened. Just the CEL is on, and I believe the jeep runs in safe mode.

If the P1694 is lighting the MIL, the manual suggests that it's bus failure to the PCM itself. That would make sense if the engine itself is quitting. The tranny code would follow from that, since obviously if the PCM is dead, the TCM will lose its communication too. You might want to check very carefully at the connectors themselves, wiggle some wires, look for chafing anywhere, and double check all your grounds. Don't neglect that strap on the back of the engine, which I have found even on my 99 can look good even when it's reduced to little more than powder.

After that, you may have to consider the possibility of a fault in the PCM itself.

Check the plugs to the PCM for loose connection or corrosion.

What is the PCM and where is it. Thank you.

Powertrain control module, "computer"

Next to the airbox.

The key thing works on my 97..

seanyb505 said:

The key thing works on my 97..

Click to expand...

We've been over this a few times, it works on pre-97 and some 97's but nothing beyond.

I haven't had a chance to check and see if it throws the same codes as a code reader will, I was told that it didn't but that remains to be seen.

Sweet Baby Jesus... I have the exact same problem (year, everything. 100Kmi) and it's driving me insane.

Has anybody gotten an update to this unfortunate situation?

I found out the root of this problem was corrosion on the main bus connections to the PCM, I just pulled them sprayed a little WD40 on them and then thi them with Dielectric gease. Haven't had the issue since then.

good answer

Thanks again Cart, hope this works for me.

Well, it turns out that the headers I put on were contacting the wires to the CPS. Melted right through the loom and down to the wire about 1 1/2" long where it was hitting the 'heat'.

I guess the CPS was grounding out and causing the PCM to fail-safe itself.

WHAT A PITA that thing is to get out!

I'll not have those troubles again though. After getting the blasted thing out, I could see the extent of the damage and decided to try to fix it rather than spend the cool C-note. So I broke out the soldering iron and went at it making sure to cut out any corroded areas out of each lead. Some shrink-wrap, elec-tape, and a new stretch of loom, (<-is that what it's called?), along with a resistance (ohm) test (should read ifinite @ a 1K-10K setting for my year-'98 [I got a 624]), and I felt good enough to give it a try...

But how to get this *&&$^# thing back in there?! I came across a genious idea somebody posted.

Basically this: I took the dremel tool and a cutoff wheel to the mounting holes and made nothches out of them instead so I won't have to take the bolts all the way out again. I then carefully threaded the bolts back in a little and slid the CPS back on. Tightened it up with my trusty 3/8's ratchet-10"extension-wobble-10"w/wobble extension-11mm socket.

(BTW- disconnecting the front sway bar and jacking the front drivers side way-up gave me just enough room to not have to touch any other bolts to reach the CPS and it's horrible placement!)

Well, all done! Thanks for all the help guys!~

Sh!t! I forgot to ziptie the wires! lol Anyway, she's running great with no more P0700 / P1694 codes! Gotta go- thanks again!

key thing worked on my 99 XJ but for some reason now it isn't and my truck isn't moving. tach and speedo drop out on me and the jeep won't shift at all. anyone have any ideas did cleaning the nss work?

citizenatlarge said:

But how to get this *&&$^# thing back in there?! I came across a genious idea somebody posted.

Basically this: I took the dremel tool and a cutoff wheel to the mounting holes and made nothches out of them instead so I won't have to take the bolts all the way out again. I then carefully threaded the bolts back in a little and slid the CPS back on. Tightened it up with my trusty 3/8's ratchet-10"extension-wobble-10"w/wobble extension-11mm socket.

Click to expand...

I think credit for this one goes to "5-90"