1999 Chrysler T&C - Speed Sensor fails 2nd time in 4 month

There are 2 sensors that could cause that problem, the input and output speed sensor, Did they replace both of them?? The output sensor always causes the speedo to not work. Glenn Beasley Chrysler Tech

Thank you for asking the question. - It made me remember now: First time this happened speedo didn't work, but now it is working. Apart from this difference, everything else is the same. So it must have been output sensor the first time and input this time around. Also I think they replaced only sensor that didn't work - output. Repair cost me $72, which is probably too little for replacing the pair of them, the price of one without labor being about $30.

Additional question: Is it typical for these sensors to break down after certain time or mileage? The fact that they broke one after another makes me think that it is either that or some other deeper problem.

Thanks for you help.

You are right. - It was too early to jump to the conclusion that it is the same sensor. In fact it looks more likely that it is an input sensor while he first time it was the output one. - See reply by "maxpower" in this thread.

I'll take the van to repairs Monday morning and hope this problem will be diagnosed and fixed. What other conditions may cause the limp mode? I guess sensors failure is not the most serious of them.

IP.

I have seen these sensors go out very early, and some that just don't go bad,I keep a set of them in my wife's 2003 Sebring just as a safety precaution, I would check to see what the fault code is before just tossing parts at it.

Yep - same sensor part numbers are used on many DC cars of the last several years. It is well known and accepted that they fail periodically (they are magnetic/metal sensing type sensors, and my guess is that the magnets just gradually weaken until they cross the threshold of working/not working - supported by the fact that they often get intermittent/temperature/speed dependent - tranny going in and out of limp mode several times on same trip, etc.). I know that many frequent flyers on the 300M Enthusiasts Club keep spares in the glove compartment. *SO*, statistically, it would not be such a strange occurence for failures of the two sensors to occur within a couple of months of each other (happened to me on my '99 Concorde - both times it was a sensor - first one, then the other - I forget which was the first to go).

FWIW, it may be that the output sensors *seem* to fail when they actually would work again by cleaning accumulated metal particles off the tip (the sensor sends pulses to the computer generated by the cogs of a spline passing by it - if the sensor tip gets coated with metal particles, it senses metal all the time so pulses don't get generated.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

So where do you keep your spare ones at now Bill?

I don't keep spares. I walk on the wild side! 8^)

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Thats like saying she loves me she loves me not, she loves me......etc

Talking of the wild-side... It really makes me weary taking the long trips with this van - you never know when one of these sensors will fail again. Even if I kept spare ones I wouldn't know how to replace them. It was mentioned on this group that it is easy, but I opened the hood and couldn't even locate the transmission, let alone replace the sensor. Also I noticed that when they did it in the shop they lifted the car and did some work underneath it, so it means the transmission is somewhere underneath, which would probably make it hard to do this type of work while stopping on the side of the road if it breaks down on the long trip unless you crawl under the car. I think it is high time for Chrysler's engineers to think how to make their cars more reliable.

IP.

The sensor is under the vehicle and fairly easy to access. The sensors are easy to find if you follow the wiring and can identify the transaxle which is under the driver side. You carefully unclip the electrical connector, unscrew the sensor, replace with a new one (do not overtighten as they are plastic if memory serves correctly, and then inspect, clean if necessary and re-attach the connector. Basically about 5-10 minutes overall provided you can get access and have a large adjustable wrench or the correct deep socket.

These vans are fairly dependable and even one of these sensors fail (I've seen 3 failures in 5 different vehicles over the last 14 years), the limp mode (2nd gear) will allow you to get it home or to a service center.

Bob