Hello all,

We recently pulled the engine in my '01 XJ and rebuilt the bottom end along with a few other various parts. After putting it back in and attempting to start it last night, we ran into some issues and we're stuck.

-No guages

- Cranks and starts, revs like mad, dies after a second or 2

We checked the codes and it's giving us a P1698, P1694, and a P1686

Im really pretty nervous it's the PCM. We had an incorrect connection at one point and ran current the wrong way so I am feeling there's a good chance we did fry it, however Im not even sure how to track the problem down at this point.

Im more hoping that it's simply a bad connection somewhere (certainly cannot find one though, we looked at every fuse under the hood and in the fuse box inside the cabin and have tried to doublecheck all the wires under the hood).

Anyone experience this before and have any tips on where to start tracking it down? We're in over our heads.

Thanks!

 

Fault P1698 is for a loss of communication between the PCM and the TCM.

Fault P1694 is for Bus communication failure to PCM.

Fault P1686 is No SKIM BUS Messages Received - - No CCD/J1850 messages received from the Smart Key Immobilizer Module (SKIM).

(It's looking for a smart key for some reason. Does the 01 XJ Key use SKIM?)


It's sure hollering about that PCM. I'd guess you missed a connection somewhere.

Did you re-establish all the engine grounds when you re-installed the engine?

 

As far as I know we did. We certainly tried to triple check everything. I suppose it is possible we missed one, that seems to be the most likely (and desirable) solution.

 

If you search for each of those trouble codes you'll similar issues.

No gauges, high rev and cut off after 2 seconds.

Check your ground connections first.

 

Not sure what you mean - assuming all grounds are tight (which to the best of my knowledge they are) are we indeed looking at a bad PCM?

I'll be checking all of the connections again next I get out there (my Jeep is an hour away at my father-in-law's while being rebuilt) and assuming that theyre good I dont know where to go from there.

Based on what I could find for each code, it still points to ECM, but my wife has suggested that similar issues and the same codes come from a wire near the transmission which I cannot place in my head - not sure what shes getting at. Shes paraphrasing her internet searches to me.

Really appreciate the feedback and I apologize for being so vague. All I do know is what the codes come up (CPS, TCM, and SKIM) and Im trying to make sense of it.

 

I could see a faulty ECM causing those codes, yes.

I screwed up an ECM a couple years back by throwing a spark in the relay box.

 

High rev could be massive vacuum leak common area intake and exhaust no seated on head very common issue climb underneath loook up with fflash light .

 

So noted.

I really appreciate all the feedback. Im going to triple-check all the wiring both for correct connections and to see if anything is corroded. Hopefully I will find something.

Oh, and to answer a question above, there is no visible chip on the key, and my buddy who has an '01 XJ insists it DOESNT use SKIM, but I've always thought it did.