2000 Chrysler Cirrus engine jerking while in reverse, drive and also while sitting in driveway. Seems like while in drive/reverse car wants to shut down. Check Engine light on, was flashing for a minute now solid. What could we look at first?

test with meter --solenoids can overheat short get sticky or just plain old fail

Sounds like a speed sensor, I will look into that, but if the speedometer isn't working, its either cable, or electronic. Being a 2000, I'm guessing electronic. Chrysler have a lot of electronics on the transmission, as they are electronic themselves. I had an alternator go bad and my battery died, and the car wouldn't shift, it actually down shifted while driving. Have your battery and alternator checked first, then sensors. Like shift silinoid, speed sensor etc.

I'm not familiar with YOUR Chrysler, BUT... my brother' father-in-law had a Buick [about 1998 model] that would NOT shift into any gear UNLESS the brake pedal was FULLY DEPRESSED!!!!!

I could move the shift lever into any of the indicator positions, but the transmission would not engage if my foot was not firmly on the brake pedal while selecting a gear position!

check crankshaft sensor.

what is the code,maybe misfire,

IT WOULD BE NICE IF YOU TOLD US THE ENGINE SIZE;STRAIGHT OR AUTO TRANS,AC ETC.
The 3.9 LT V6 engines back then had bad lower distributor/camshaft bushing. IF your car missfires-is hard to start-or tries to run backwards upon shutdown it may be this.
Engine will have to be put on analyzer(to show vaariable timing caused by bushing)=easy to Dx and may be covered by warranty .

sounds like the cooling fan(s) are not working. possible a disconnected plug near radiator . my guess is the mech forgot to plug it back in. check around the radiator for any plugs that are just hanging loose . also check the fuses . there may be one for cooling fan and see if it is burned out.

Fuel pump and filter were changed how long ago, and how many miles ago? Did they change the wrong thing(s)? What engine is in your Cirrus?

I had a car do the same thing. It turned out it was the PCM. Also if that does'nt work try replacing the Crank sensor.

a distributer fixed one we had a problem with.