How do you clear codes

How do you clear codes so that your service engine light will turn off and you can see if the repair you did worked? The car in question is a 97 Dodge Neon. A friend told me that you could just disconect your car battery for about 10 minutes and that would clear it out, another said cars built after 1995 wouldn’t do it and they have to be removed via a computer.

You might try the auto parts store. Advance or autozone. They have an OBD device to plug into the car to clear the codes.

Really? I know they can read the codes but didn’t know they could erase them, you would have thunk they would have said so when I got the code read, bought the part.

Disconnect your battery for 30 seconds…

I tried that and the light didn’t go off. My friend says it has to be for at least 10 minutes, plus I need to turn my headlight switch to on.

You know, this really won’t help you. If you have fixed the problem, then the light will go off after enough drive cycles. If you haven’t really fixed it, then it will stay on.
If you reset the light, you still won’t know if you have fixed it until the same number of drive cycles go by and the light doesn’t come back on.

$35…Read and Clear…

My 2005 F-150 clears off a 30 second battery disconnect.

You are correct. At least in AZ, AutoZone has agreeded to not clear codes. There were automotive trade groups that claimed if they cleared codes that they would be in the business of auto repair.

Had a check engine light come on on my brother’s Nissan Quest. (Same thing as a Mercury Villager) Was an O2 sensor code. Turned out the sensor itself was OK; there was just a broken wire coming out of the O2 sensor.

I mended the wire and then disconnected the battery for a minute. Reconnected the battery. Started engine. Check engine light came on and stayed on. Disconnected battery for 10 minutes. Check engine light still stayed on. Finally I left the battery disconnected for 1 1/2 hours. Check engine light never came back on. That was about 3 months ago.

Someone mentioned turning the headlights on to speed up the process (drain the voltage holding capacitor) but I suspect that capacitor is protected by a diode and only time will discharge it. The OP might try an “overnighter” and see if that works…

On our 1995 Neon (yes, it was OBD2) disconnecting the battery or pulling the radio fuse for a few seconds would clear the codes. I expect that the 1997 would be the same. I think that what may be happening to you is that you are clearing the codes when you disconnect the battery, but that some code – not necessarily the one you are trying to fix – is being set immediately when he ignition is turned on.

As with many Chrysler products you can almost certainly read out simplified codes yourself without tools. Follow the directions at .

How much time and money has been spent trying to “fix” CEL’s that have absolutely NOTHING to do with the serviceability of the vehicle??

Make the manufacturers build cars that are clean when they leave the factory and STAY CLEAN for the life of the vehicle. Please don’t try and force ME to spend big bucks trying to “fix” a problem that does not effect the operation of my car…You think I’m going to spend $1800 on a new exhaust system to make YOU happy?? I’m not! Sorry!

I know the OP is an older one, but in case anyone wants to know, a mechanic friend of mine showed me how to do this in ten seconds. Diconnect the Negtive battery cable, then disconnect the positive battery cable. Then hold the ends of the two cables together for at least ten seconds, making sure the connectors on the cables are making good contact with each other. This speeds up the discharge of any residual charge left in the system. Reconnect the cables in the reverse order. Codes cleared.