1997 Plymouth Voyager not sure what's going on

CHRISTINAJASMINE6

MEMBER
1997 PLYMOUTH VOYAGER
6 CYL
FWD
AUTOMATIC
200,000 MILES

We just bought this Voyager (used). It drove fine at first but after about 45 min continuous driving the check engine light came on. 30 minutes after that the tach needle started to jump ahead, the van started to surge while driving, and seemed like gears weren't shifting. Had it put an a computer (where we bought it), was told to change the speed output sensor. Within 10 minutes after doing this car started having a very rough take off from stops. Tach needle not jumping but doesn't seem to want to start going after being stopped at a light or sign. Also again after getting warmed up it doesn't seem to be changing gears, RPMs hit 4000 ast 40MPH.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Hi Christinajasmine6. Welcome to the forum. When the Transmission Computer detects a problem, it defaults to "limp-in" mode meaning it stays in second gear. That will make it appear to have low power when beginning to move from a stop. To reset the computer, you must turn the ignition switch off and restart the engine.

There are two sensors, the input speed sensor and the output speed sensor. The diagnostic fault code will indicate which sensor has the problem. You will need a scanner that can access the Transmission Computer to read the code(s). Simple code readers that many people have can only read codes from the Engine Computer. Typically it will have code P0700 which just means there is at least one code in the Transmission Computer.

All mechanics and most dealers have the higher class equipment that will access the Transmission Computer. You might want to have the code(s) read again to be sure the correct sensor was replaced. I hope it's as simple as the wrong one was changed.

Caradiodoc