Contour Enthusiasts Group Archives Forums Modifications Transaxle A TSS Symptom or other CD4E concern?

Lately I have been experiencing what I believe is a shift problem cruising @ hwy speed. Briefly when @ a steady 55-65 mph speed and rpm @ 2200, I will get a sudden increase in rpm to about 3000 and feel what I believe is a shift out of overdrive. This will happen 2 or 3 times and then settle back to its normal rpm reading in high gear. It does not feel like a hard shift. I am not getting any blinking o/d light. I checked for any obdI codes any there is nothing related to transmission. This symptom seems to occur when transmission not fully warm and under slight uphill conditions. I do not experience this everyday but it has been becoming more frequent.

I have been reading previous posts and doing searches to find any similar symptoms. It seems the Turbine Speed Sensor (TSS) problems have caused a shift bang betweeen 1st and 2nd gear. I have reguarly serviced the ATF w/ synthetic. I guess I need some confirmation I am going down the correct diagnostic path. It's hard for me to believe this symptom is fuel or ignition related. I did get a memory code 639 ( Transmission Speed sensor circuit fault) 9 months ago, but I was not experiencing this problem then.

Any insight from a CD4E guru would be greatly appreciated!

Any insight from a CD4E guru would be greatly appreciated!

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Anybody have an educated opinion?

Tony2005
Thanks for the links to relative threads. I read some of them before I posted this problem.

As for the ATF change, I can rule that out because I have been diligent fluid change and just did one 1500 miles ago. The TSS symptoms seem to deal with the shift bang from 1 to 2. I am not experiencing that problem. Plus I do not have a blinking O/D light.

According to one thread about the MLPS, I may have one that is intermittenly acting up under certain conditions. It appears that it's shifting momentarily out of OD, down to 3rd, and that back into O/D all within 2 or 3 seconds.

Has anyone else been in my shoes and replaced the MLPS to solve their dilemma? I do not want to replace a sensor that is still good. I have blown my monthly budget on parts already; got both oxygen sensors on order to slip in!

I will hope for some replys and in the meantime I will do some searchs on the MLPS and common symptoms. Once again, thanks for everyone's help on this great CEG site!!!!

It could be any of the sensors, but it the only way to really tell is to have a scanner attached to the car and taken for a test drive. "A Scanner" being one that actually reads the data stream to and from the PCM. If you don't have one, such as this one for an OBD I system, you will have to have a shop do the tests for you. Look at paying around $45 for the tests.

If your not getting a CEL or Flashing O/D light, then that rules out the only other thing it could be, which is a slipping torque convertor.

a95:

i am relatively transmission ignorant, but i'm going to post this only because i had similar, yet more pronounced symptoms a few months ago. i want to emphasize that i have no idea whether or not this could be your problem.

my symptoms included:

1. abrupt shifting behavior (at times, VERY abrupt)
2. primarily occured at highway speeds
3. continuous fluctuations in rpm

after diagnostic tests at my dealership, it was determined that my range sensor was bad. i don't know much about this sensor, so i can't offer any skinny on that.

at the same time, my tss was bad, which may have made my symptoms worse than yours. i later changed the tss myself, (5 min job).

it almost seems to me that you have a milder version of what i had. but like i said, this is just my impression, and i can't say anything with certainty.

perhaps some of the experienced folks here could offer some words to either rule in or rule out my observation.

my range sensor replacement at the dealership cost an arm and a leg. i don't know where this sensor is located, but man -- if this is your problem, do it yourself, if possible...

thanks again, tony. so mlps = range sensor. got it.

so, a95, the only potential benefit of my previous post was to state that i had similar symptoms and the fix was the mlps.

whatever your solution, i hope it's cheaper than mine was...

Phil,

I have my own Snap-On scanner to hook up. I can go for a nice test drive and read live data pertaining to the transmission. It sucks w/ the connector under the hood. People will start pointing to the cable coming out from my hood, through my window, attached to a scanner while I am trying not to swerve off the road.

I tend to lean towards the MLPS possible being intermitently causing this drivability problem. One other thing to point out is I had to repair one of the wires off the MLPS that was severed from an accident. The battery tray had cut into the wire when I got hit in the LF fender. I fixed that problem after I found a continuous memory code (forgot #) related to the range sensor. That was 2-3 years ago though. Also, it seems ford has sold many range sensors over the years. Plus, jsark said "had similar symptoms and the fix was the mlps."

I know both jobs, with some luck (it's better to be lucky than good) are not too labor intensive. I know the horror stories with a fiesty TSS. The range sensor is accessible with few minor obstructions.

This weekend I will hook up to the PCM and post back what I come up with. The funny thing is that I have not experienced any symptoms in about a week . It hard to imagine the torque converter would be slipping @ 61K when I have never abused the AT. But I guess stranger things have happened to a CD4E tranny!!