Does a 2002 Neon have to have a 2002 transmission

Tran, po605 = (transmission control module ROM self test fault detected AISIN transmission ) I would first clear the code and see if it comes back ,that will tell you that it's a real code and not just a fluke.do you see or feel any difference in the car when driven ?are your fluids full ?

You need to call your local ford dealership and have them run your vin. There are 3 different transmissions for this vehicle. Ax4n-ax4s-4f50n..then call the parts department and they can tell you....

I had the same problem with my 2002 Neon and the transmission fluid was mixing with the coolant. You cant fix it yourself...Either pull the radiator and take it to a rad shop or replace the rad as I did. If the coolant gets into the transmission you will also need a transmission flush.The fitting you are talking about has come loose from the transmission cooler tank inside the rad.Its a common problem with neons I got a new rad from NAPA and changed it myself, and it was a lot of work. Good luck. The manual also says to replace the flexible tranny lines.

check your transmission solenoids see if one went bad also check your vehicle speed sensor if its messed up sending wrong signals

I wouldn't recommend it, but if it's the same engine size and same year it will probably bolt up... the problems come with the electronics.

Hello
Welcome!
Instructions Things You'll Need:

• Wrench
• Jack and four jackstands (optional)

1. Step 1 Loosen the bolt on the negative battery cable and slide the connector off of the battery. The battery is on the right side of the engine compartment. The negative battery cable is black.
   
2. Step 2 Jack up the vehicle and place it securely on jackstands. If you cannot raise the car, remove the air filter box, battery and battery tray. These are all on the right side of the engine, connected by bolts.
   
3. Step 3 Locate the vehicle speed sensor. It is on top of the transaxle, near an inner CV joint. If your Neon has a manual transmission, the plug will be oval-shaped with three wires and connected with a bolt. Automatic transmissions will have a round plug and sensor. Use the replacement sensor as a reference while searching for the sensor.
   
4. Step 4 Disconnect the sensor. For manual transmissions, squeeze the tab on the electrical connector and pull. Unscrew the bolt holding the sensor to the transmission. The plug on automatic transmissions is held in place with a locking tab underneath the connector. Pry it open and pull off the connector. Unscrew the sensor from the transmission.
   
5. Step 5 Install the replacement vehicle speed sensor and reconnect the cable.
   
6. Step 6 Remove the air filter box and throttle body if your Neon has an automatic transmission. A second vehicle speed sensor is located on the transmission below the throttle body. It is connected in the same way as the other sensor and can be found behind two rubber hoses on the transmission housing. Replace it the same way you replaced the other sensor.
   
7. Step 7 Lower the car and replace any parts you removed to access the sensors.
   

Take your vehicle and get a computer control check on your vehicle this may help with diagnosis

The speedometer is driven by the computer which uses the Vehicle Speed Sensor, which is located on the transmission, to determine how fast the vehicle is traveling. It is not uncommon for the VSS to go out unexpectedly, usually the check engine light will come on when it malfunctions, and the computer will lock the transmission in 2nd gear, which will allow you to limp the car in to a repair shop.

Looking at the age of the vehicle - I would not invest $5000 in it.

Look in your local business pages for second-hand parts dealers, and get a quote for small garages to do the work of replacing it.

Chances are you will find a low-milage transmission for $250, and pay around $200 to have it installed - so for $450 you're good to go again.
If this was a younger vehicle, then yes I would go through dealerships to keep the logbook perfect; But at this age it's only 3 years off it's designed lifetime, and 10 year old vehicles are very low priced.

The heat exchanger in the rad header on the bottom is shot. You need a new rad, flush the coolant, change the tranny oil and filter, clean out the resevoir.