I am looking to purchase a 1995 neon that has issues. The current owners told me the car needs a new ecm but I'm not sure. She apparently went to a pick a part place and purchased one but the car died again. She has been told by a couple mechanics that the ecm was the problem that's she change it out. I haven't looked at it and I'd like to know where to start since I can't move it to a dealership and I also don't want to spend too much to fix it.
rice_eater
08-31-2007, 01:07 AM
A lot of mechanics will say "you need a new computer" as a fix all... meaning they really have no clue what the problem is, but computers are expensive and they can make money off an easy job. PCM's (or ECM's, ECU's, whatever you wanna call it) can be picked up fairly cheap used, in the $40-$50 range, but I'd make sure thats the problem first. You can check the computer for error codes by flipping the key 'on-off-on-off-on' within 5 seconds. (do not start the car, just turn key to the "on" position) The Check Engine/Service Engine Soon light will then flash in a numerical pattern, relaying a series of two digit codes. Interpretations for the codes can be found in the Error Code thread at the top of the Neon General Talk page. If the PCM is shot you will either get absolutely nothing at all (or this could mean the bulb is out) or it will relay whatever the code is for internal computer failure. Code 12 is normal (this would be one flash, 2 second pause, two flashes, 4 second pause) it just means the battery was disconnected recently. Code 55 is the 'end of transmissions' code, meaning there are no more error codes to display. Try this out, and see what the computer tells you about the car. Good luck.
dmill12000
09-10-2007, 12:14 AM
Thanks for the help. I tried what you suggested and the code said it wasn't recieving a signal from the crankshaft position sensor. My question is how much of a pain in the butt is it to change out?
rice_eater
09-10-2007, 03:06 PM
Not hard at all. Jack the car up and put the front on jackstands. Weasel yourself under the car. The crank position sensor is located on the backside of the block above the oil filter. While you're under there, check the wiring to the CPS, make sure its all in good condition and you're problem isnt caused by a short in the wiring. Disconnect the wires, take the old one out, put the new one in, reconnect the wires, and weasel yourself back out from under the car. Let the car down off the jackstands and you're good to go.
donald7150
09-10-2007, 11:02 PM
yep, and a bad crankshaft position sensor will cause the car to shut off or not start
