loss of camshaft position sensor input?

Howdy folks, I just came across these fora while searching for a solution for my problem.Here's what I have
2000 chrysler town& country awd
3.8 v-6
140Kmiles
while accelerating, especially if the engine is over 3500 rpm it will buck& miss, the tach indicates a drop in rpm, It has set a trouble code describing "loss of camshaft/crankshaft signal input. I have just replaced the cam position sensor. still doing it.
Any Ideas?

As the code narrative says "loss of camshaft or crankshaft signal input". It's common practice for shops to change both sensors to correct the problem. Just be aware this could also be a wiring, PCM, flexplate, or cam ring issue. I'd recommend inspecting the wire harnesses and connections between the sensors and the PCM. If all looks good then go with a new crankshaft sensor.

PCM = Powertrain Control Module - the engine's brain. Always disconnect the battery before disconnecting/reconnecting the PCM.

Ok time for a status report. Initially when I had this van scanned, it was at an O-really parts store, they listed but did not stock the cam sensor, their warehouse 60 miles east of me did, so I had the wife pick one up when she was in town. they did not show a crank angle sensor(I did ask).
after the cam position sensor did not resolve it,& you were kind enough to mention that this is a redundant system with both. I picked up one over the weekend& have installed it tonight. for those who do not know, the crank sensor is on the trans side of the flywheel housing, looking from the flywheel end to the front of the engine the sensor sits approx at the 3:00 position & slides out to the rear of the vehicle.
however I still am having a high speed miss accompanied with the cks/cms position loss of signal.:runaround:I have cycled& looked at the connections in both connectors for the cam& crank sensors, I did not see any corrosion or dirt in any of these. I also cycled& checked the larger connector of the engine sub-harness to main harness connector, it too also looks clean. so I am left with the connectors for the pcm? I also noticed a slight flicker in the dome lights while running the vehicle at a high idle. (~4000 rpm) could this somehow be a grounding issue? other ideas?

http://www.obd-codes.com/forums/viewtopic.php?f=2&t=3071

thanks for the link.
In your experience, how often have you seen a flex plate fail on a 3.3/3.8?

I called one tranny shop for a quote to r& r the flex plate& was told they had only seen one do it in 10 years.

the van is getting much worse now it is bucking at 2500 rpm& below. I hope to be able to get it in the shed this afternoon& remove the inspection plate& look at the flex plate.

I've never seen a flexplate go bad but, then again I might work on a dozen cars in a year as a DIYer. My experience with flexplates (FP) is based soley on what I've read on this and other forums over the past 5 years. Based on that, the main complaint I've read regarding flexplates are related to noises. Many times people are at their wits end trying to nail down the source of a whine, tick or grinding noise. They spend days even weeks changing parts and researching. They then discover the flexplate has cracked or warped. The P1391 issue does come up but not as often. I recall at least one or two verified FP/P1391 fixes. Unforunately many will post the problem without posting verifying the fix.

There are a couple P1391 posts going on right now. Here's one that illustrates an unfortunate mistake. I'm happy to hear you're going to inspect your FP. Read through this and you'll understand why. http://forum.chryslerminivan.net/showthread.php?t=14323

There is a TSB related to P1391 codes involving chaffed wire harnesses routed near the transmission. Of course now I can't find it.

well after going a while over winter,& being busy, this van took a back burner as we had a spare vehicle, I did not have the means to drop the tranny, so I took it to a nearby shop here are some pics of what they found today.


http://i155.photobucket.com/albums/s294/russell_smith93/forum%20source%20pics/SUNP0026.jpg
http://i155.photobucket.com/albums/s294/russell_smith93/forum%20source%20pics/SUNP0024.jpg
http://i155.photobucket.com/albums/s294/russell_smith93/forum%20source%20pics/SUNP0025.jpg

Wow. A bit blurry but I can see that's one ugly flexplate. I'm wondering how it ran at all. The crankshaft signal was the culprit. The engine can run (not start) without the camshaft signal but you loose the crank signal and you're dead in the water. Lucky it didn't die out in the sticks somewhere. Thanks for coming back and posting this. It tells the whole story.

How much did they charge to fix this and how much was the flexplate?

it is still on the lift as we speak, they had just dropped the transaxle his am before I stopped by.

sorry to forget to reply, the total bill was ~700, I had mentally budgeted ~1000