2004 s type 3.0
102,000 Mi.

Hi guys. Tonight coming up the mountain 8443ft elevation, Got a trans warning and reduced performance warning and felt like it was ******* or loss of power. I pulled into a turn out and stopped. I put the shifter in neutral then back to drive. everything seemed okay till I started to accelerate. It was stuck in high gear. The manual shifter 2-5 did nothing either. I babied it back up to speed and realized the the worst part of the climb was yet to come so I got a running start at it and got it up to 70. by the time I got to the top I was doing about 45. Still in high gear. code is P1643 and will not shift into lower gears. Any ideas please? TIA

 

From what I've read - a poor battery condition can cause this P1643 (I.e voltage/cold cranking amps , aswell as the selector cable bolts on the side of the trans coming loose , also various connectors Including the trans connector to the pcm , and worst case scenario is a fault with the ecm , quite a few things to check . If you type P1643 in to the search bar , and have a read up !

 

It has a new bat. All conns at the bat tight and very clean. I will check the bolts and the other cons. Thank you, John

 

Don't think for a second that because your battery is new that it must be as good as new I have purchest several brand new battery that were junk out of the box , have it load tested ! Also I was rong about the ecm being worst case scenario ! Although is does sound bad ! But it seems that the wireing loom can chafe or brake wires to cause this issue as well ! Good luck hope you find the problem easerly !