2002 chrysler concorde lx low idle

Yes, this is most likely a shift solenoid but I would do the dummy check on the fluid level first. Tranny oil also needs to be changed every 60000 miles on most vehicles.

The 3.5 is a great engine and in the Concorde pretty efficient for sure over 20 MPG. The 3.5 HO is 1st generation and has a 10.4 to 1 comp ratio. 89 octane is required later engines after 1998 had the compression ration lowered to 9.9 to 1 and 87 might be acceptable. Scheduled spark-plug change is usually 60K miles. If plugs have not been changed than I would certainty start with them. Check tire pressure against the driver door recommended. I expect if all else is well that at 60 MPH just under 2000 RPM in over drive and smooth..

This engine was built in Chrysler's Trenton engine plant in MI and is considered one of the best power planets at the time.

Possibly a fuel issue, but have the pressure checked before condemning the pump. Is the gas filter good? And the air filter?

It could be an idling issue-idle too low. Check if can be raised, or if idle control motor or valve needs service. Idle should be around 750 rpm, in drive gear, maybe a bit lower, not below 650 rpm, though.

You either have a TCM (Transmission Control Module) issus, or the electronics in the transmission has failed.

IDLE SPEED COULD BE LOW CHECK IDLE SPEED SHOULD BE 650 - 750 RPM.CHECK IDLE SPEED IF OKAY YOU COULD HAVE FAULTY FUEL PUMP OR VECHICLE COULD BE GETTING HOT OVERHEATING SHUTTING OFF ENGINE.YOUR EGR VALVE OR PCV VALVE STUCK OPEN.CODE SCAN FOR FAULT CODES.

Maybe a short to the TPS or something shorting it out. There's also the IAC that really controls the idle but usually it will cause the RPM's to go up and down a little erratic if bad. The MAF sensor can cause major problems as well but since you already swapped the TPS and it helped and then stopped I would focus on that sensor and especially it's wiring to and from the ECM. Be careful with the sensor signal wire to the ECM can blow it if more than 5v passes or spikes.

after my 2003 chrysler concorde is warm I slow down from the hwy and right before I stop my car shifts to LOW gear and stays there until I turn my car off and start it.

Computer firmware needs upgrade

Take your car to a Chrysler dealer shop and have them update the transmission program.As your tranny wears it loses it shift point and stutters between 40 - 45 mph looking for the right gear to change to..Had same problem in 94 Concorde and 94 T&C minivan.Reprogramming tranny fixed both cars.

one unit that operates ratio changes and is connected to the engine is that vacuum operated actuator on the transmission
it is possible that that unit is failing , vacuum hose is leaking and that will cause ratio changes as the vacuum varies
run the fault codes to check for wiring problems or VSS or TCM problems as well