Jeep: Transmission codes, jeep cherokee sport, jeep cherokee

Question
Kelly,  I have a 98 Jeep Cherokee Sport with a inline 6, automatic transmission.  My problem is no matter if I'm sitting at a light or if I'm driving at different speeds the MIL comes on.
Even if it's raining or if it's nice outside it will come on for a few days then it will go out.  Few days later and the light is back on again.  When I pull the codes they are in this order, P1698 No mess received from TCM, P0700 Transmission system malfunction,P1694 No mess received from ECM. I cleaned the wire connections where both TCM and ECM plugs into and checked for loose wires and everything checks out. Took it to a transmission shop and they said transmission oil looks good, not slipping and shifts fine. Went to a different shop and they wanted to charge me $1800.00 to rebuild even if the transmission seems fine to me and the first shop. I'm guessing that the TCM is bad or the ECM is bad or maybe both. If you could think of anything please let me know.  Thanks ,Robert  

Answer
Hi Robert,

I see you have access to an obdII code reader. I first off like to say is that I would think hard and twice before replacing the Transmission for an intermittent code, secondly have you been to the dealer recently to have a flash update on the PCM?.You most likely need the PCM flashed. I seem to recall a TSB that came out in 1997 in regards to xj.Below is listed a caution that is listed on most of the TSB's regarding PCM Flash reprograming on Jeep products. It might help to explain all the codes you are getting. Hope this helps.



NOTE: DUE TO THE PCM REPROGRAMMING PROCEDURE, A DTC MAY BE SET IN OTHER MODULES (EATX, BCM, MIC, SKIM) WITHIN THE VEHICLE, IF SO EQUIPPED. SOME DTC'S MAY CAUSE THE MIL TO ILLUMINATE. ALL DTC'S RELATE TO A LOSS OF COMMUNICATIONS WITH THE MODULE THAT IS BEING REPROGRAMMED. CHECK ALL MODULES, RECORD THE FAULTS, AND ERASE THESE FAULTS PRIOR TO RETURNING THE VEHICLE TO THE CUSTOMER. ERASE ANY FAULTS IN THE PCM ONLY AFTER ALL OTHER MODULES HAVE HAD THEIR FAULTS ERASED.