Expert: Roland Finston - 10/10/2011

Question
QUESTION: i read you answer on the code p 1698 .i have a 2003 the trany is not shifting and all the lights on the shifting guide are on and the engine light i put the computer and i got p1698 and p0500 please advise
david
thanks

ANSWER: Those codes are: for 0500 no vehicle speed sensor signal (which could be the sensor, its wiring or the pcm may have failed.
         and for 1698 no digital data between the tcm and the pcm and could be a connection  problem or a failure of the tcm or pcm. The two together might be pointing to a failed pcm.
You didn't give me a model/engine size nor any history of this so I can't offer more now. Let me know further.
Roland

---------- FOLLOW-UP ----------

QUESTION: v6  3.3 2003 dodge caravan the van just did 200 mile trip and the trany fluid is clear red no smell i dond recall if these lights were on when igot the vehicle but week later it was ,were do i check all connections speed censor could it be only speed censor causing all

Answer
The two speed sensors are on the side of the transmission, about mid-line, one in front of the vertical shift rod is the input torque converter speed sensor, one behind the shift rod is the output sensor (which gives the vehicle road speed). Each has a plug which goes to the transmission controller. I am wondering about why a sensor, either one, would be the problem because those set a code, either a  0720 output or an 0725 input, when they fail. The 0500 is saying that the pcm doesn't see a vehicle speed sense which comes from the TCM, so if your speedo is working then the sensor is ok and there is something wrong with the PCM or the connection of the TCM to the PCM. I haven't seen this code combo before and the only common element is a problem with the PCM or its input from the TCM. You might do well to check the plugs at the pcm and the harness and the plug at the TCM for any sign of looseness or damage. But you might do well to ask a good shop.