Speed sensor maybe transmisson????

[c_evans1979]

What I have is a 99 Dodge Caravan with a 3.3

When backing out of a parking spot then driving the van jerked and then wouldnt shift went into "limp mode" well I got it home and parked it till today I went to drive it around the block to the back of my house to work on the speed sensor and half way around it jerked again and i lost drive totally but reverse still works. So I drove it in reverse around the block and the started working on it. I replaced the out put speed sensor and disconected the battery this did not work so Im thinking the transmission is gone.

If someone could give me an idea want to do next it would help big time....Thank you for all the help ahead of time.....Chris

[allenprimo913]

did you replaced the input sensor too? i have same problem the first it jerks when it shift after the 2nd gear and runs fine. but when you slow down it shift then jerks again but never had problem with reverse or forward.

this is all i did:

1. replaced tranny filter and drained fluid with atf+4 = did not fix the jerking

2. adjsuted shift cable = did not fix the jerking

3. found out the tranny mount rubber on the front busted, i replaced it = did not fix the jerking either

4. found loose hose leaking tranny fluid from the cooler fixed but still jerks

5. i replaced both sensors , input & output so far its ok as it was.

for some reason , i dont know why still doing it a little sometimes but not all the time
im not happy with it but make it buy me sometime to keep going till i have enough money for new tranny.

my advise bring it to the shop if you're not experience, i spent almost $500 just for parts not including my labor and still im not 100% sure if it fix my problem.

just a suggestion.

[RIP]

Good tips from allenprimo. Just want to emphasize step #1 above. It will give you a chance to see if their's debrie in the fluid pan. If there's anything more than fuz on the magnets, you need a new tranny. Also have a shop check for transmission fault codes. These are only accessable by a transmission specific scanner.

[allenprimo913]

hello,

after driving my 1998 voyager for few days, the jerk is coming back right after 2nd gear, it jiggles then run fine then jigggle when youre on stop.

i dont think replacing those 2 sensors which costed me $40 helps. i read on one post over here that he replaced the TPS and shifting problem went away.

i dont wanna spend more money on to it not unless it fix the problem, any suggestion?

tnks

[RIP]

First. None of us have magic wands and crystal balls. We are all guessing. Educated guessing to some degree but, guessing especially from states away.

http://www.autozone.com/shopping/rep...00c1528003c4e3 Click the pics to blow them up. Get your meter out and test the TPS. Keep in mind it can test fine all day and still be bad. Same for most sensors.

The only time you change the output speed sensor is if you're having shift problems AND an erratic speedometer. They use the same output signal. The logical choice would have been the input turbine speed sensor. Except to check the reference voltage with a voltmeter you'll need an oscilloscope to test it. Cheaper and quicker to just change it. Inspect the wire harness and connections for chaffing, corrosion, and security first.

Are you seeing the service engine soon light come on?

[allenprimo913]

thanks for the response

i did replaced both sensors and it did run smoother for few days but now the jerks back but not as bad as before but still you can feel it.

the funny thing too is i dont have any codes or engine light comes on , everything is normal except that lil jerk.

anyway, my rpm and idling are ok and no signs of erratic abnormalities and changing the TPS i dont think will help either.

i replaced a busted tranny front mount i thought that was the problem but it wasnt. the rest of the mounts seems ok.

maybe i have to drain the tranny fluid one more time and see what happens.

my another issue is THE LIGHTS FOR MY defogger, back wiper, ac are blinking and i dont know how to reset the climate control. any help would be nice and appreciated.

thank you again

[RIP]

Try a climate control system calibration to clear the lights. There are several ways to do that listed in this link. Hope one works: http://www.allpar.com/fix/codes-climate.html Only perform these procedures if your A/C is working, otherwise, lights will be flashing till you fix the A/C.

Yup. Sounds like you know dropping the trans pan to change the fluid only changes about a third at best. Another change wouldn't hurt. Consider buying a pump and suck it out the dipstick.

[allenprimo913]

hi rip,

how do you new flash program the TCM?

or how do uou reprrogram it? somebody mentioned that maybe it needs to be reprogram for the shifting gear of the transmission

any clue?

[4breezes]

We've just been through the same thing. Symptoms were much the same as posted above.

I just entered a post on our experiences, "Successful Transmission Fix." Read that one also.