The check engine light (service engine soon) comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to AutoZone or a shop that has an OBD2 scanner, or for 1995 and earlier models, an OBD1 scanner, While a scanner will not give you the magic answer, it will give you a code that narrows down the problem area.
Check alternator with a voltmeter A fully charged battery should read approx. 12.8 volts without engine running With engine running reading should be approx. 13.8 - 14.2 volts
Only the computer can tell what made your check engine light come on. It could be your battery. If your battery is bad, replace it and see if that solves the problem. If it does not, then you will have to connect your car to the computer and find out why the check engine light came on.
Replacing the battery should not have triggered the check engine light. The check engine light comes on when there is a problem with the emission system. Saying that, I would drive it for a while to see if the light does go out. If the light does not go out have the ECU scanned to retrieve the trouble code. Then use this code to diagnose the problem.
your Alternator
i need to know if it is alright to drive this car like this Sounds like you left a wire loose, or blew a fuse. If the battery light is on, the alternator is not charging properly and it is not safe to drive.
My check engine light came on because the terminals were not connected tightly. no. quite the contrary. if you have a "check engine" light on, disconnecting, or in this case replacing the battery will turn it off. you have a different problem.
I know that this might sound stupid, but I also have a 2004 Dodge Neon SXT and the last time my check engine light came on, I noticed that my tires were a little low, and the light went off after they were filled. Hope this helps!
My rpm light came on but not my check engine light so what does that mean when the rpm light is on
Did you reset the Check Engine light? If not, reset by disconnecting the negative battery cable for a couple of minutes. This will erase the computer. Reconnect the battery cable and if everything is OK, the Check Engine light should be off.
Most likely the alt. quit. The battery ran out of charge. Charge the battery, start the engine, and check volts on the battery, anything less than 14 volts, like 12.3 or so, check wires, and most likely change the alt.
get a amp meter they are fairly cheap check both battery cables to make sure they are tight. then check battery cables to make sure both are working properly then check starter wiring and alternator wiring. If none of them are the cause check the voltage regulator
reset check engine lightDisconnect the negative battery termnal for five minutes.