Need some help with my 08 Grand Caravan 3.8, 90k miles. A few days ago she was running great. I changed the oil, did the interval reset, and headed out for dinner with the family. At 60 mph, it stuttered and I got a traction control light and a check engine. It was hard to start after that and wanted to stall. Codes came up P0339 intermittent crank position sensor, and P1128 fail to achieve closed loop. Replaced CPS with Autozone part...no change. Upon further reading on the forum, installed CPS from dealer....same deal, only worse today. Cranks forever to start. Yesterday it started fine cold and ran perfect for 5-10 minutes before codes and limp mode kicked in. Now it's throwing a code when cranking and it takes 5-10 seconds to start. Traced entire harness and found no chafing or breaks. Good 5 volt reference at CPS. Replaced battery for good measure. Any ideas out there? My buddy with a good snap on scanner says cam crank sync is not there and CPS signal is sketchy. Looking for better ideas than a broken flexplate...please God not that.

 

Found this TSB that relates to P0339 and P1128 codes. Apparently doesn't apply to 08s but it's a dead ringer for what you are experiencing. It involves adding a shim to the crank sensor installation or ... I'll let you read it.

https://dodgeforum.com/forum/2607898-post7.html

 

Thank you, I tried it this morning on all three sensors and no luck so far. Tried .010" and .020". Weird thing is sometimes the car starts instantly and feels like it will be fine, then it dies and codes. Other times it cranks and cranks. I pulled the connector again, as well as all the connectors to the PCM, inspected, and gave a squirt of contact cleaner. Still no good. Ground to engine is great. Sometimes idles fine and craps when I put in drive. Sometimes it drives a bit and then just quits.

Is the cam sensor suspect even if it's not reading a cam code? It's gonna be something stupid, but I can't find it right now.

 

Have you checked the wiring to the crank sensor to see if you are getting voltage or ground where you are supposed to? On the older 3.8's the cam and crank sensor shared either a ground or positive (can't remember which right now) so yes I would say the cam sensor could be suspect.

 

I have a solid 5 volts on the two outside pins, and a good ground on the center pin.

This morning it fired right up, idled perfect, no codes. I backed out of the drive just fine, and the instant I shifted to drive it died and was hard to restart.

Still clueless.

 

Will try to inspect flex plate tonight. I will post updates. Any other ideas out there? Is a faulty crank position signal consistent with the traction control light?

 

Sometimes the Problem is the CAM sensor instead of the crank... Unplug the Cam sensor, and see if your car runs. Cam sensor should be above the timing chain cover.
Yes, Trac light will come ON if CEL comes ON for some of the codes. So ignore the Trac light for now.

 

P0339 resolved. My buddy found the blue reference wire from the cam sensor was broken inside the insulation. Break was near the battery where harness wraps over transmission. No marks on the outside sheathing, no marks on the wire, just hours of feeling each wire after pulling the harnesses apart until he found one that felt wrong. He soldered and used heat shrink, and it's been good for 100 miles so far, which is 99.5 miles better than since the problem started. He charged me $250 for HOURS of searching....good to have friends. I think he deserves a case of beer on top of the money. Lousy quality 6 strand wire and terrible job of using harness wrap that's so loose that a wire will break without leaving a mark on the harness. Good to know you can drive on either the cam or crank sensor if necessary, but it's not fun.

 

Yup. Add that case of beer. Imagine what it would have cost at a dealership or even some local shop. They may have spent all that time and not found it at all and handed you a whole lot bigger bill. Just wondering. Did your friend try shaking wire harnesses while checking wire continuity at the same time. Might have speeded things up.

 

He did wiggle test the harness, which got him to the right harness. It just took forever to find the break because the wire strands were broken but the insulation looked fine.