My malfunction indicator light is on dodge neon 2001: got codes P1684,P0455

this code is when the bat is disconnected or low volts 8.8 and under my suggestion chek that the altenater is putting out properly if it is try a new battery

Pull all the fuses and reinsert them. Could be corrosion and this will take care of it. After that is wire chasing with an OHM meter.

P0455 Evaporative Emission Control System Leak Detected (gross leak)
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Multi-cardiag M8 CDP Pro 3 in 1

Where have you been since 1980,some 32 model years?

The MIL Lamp,Check Light or any dash light
is an OBD2 (On-Board-Diagnostic) light indicating
a possible vehicle system malfunction

Check for codes --- within a couple of days
Diagnose system--soon
Repair or stop using the vehicle, if repairs can
not be made in a week or so

P1684=The battery has been disconnected within the last 50 starts

P0171=System Too Lean Bank 1,this is an oxygen sensor

P0700: EATX Controller DTC present
P1684: Battery was desconnected
P0442: EVAP leak monitor medium (.040). Leak detected.
P0455: EVAP leak monitor large. Leak detected.
P0456: EVAP leak monitor small (.020). Leak detected.

I suggest check the lines and flow it down to the ldp (leak detection pump) that is just behind the steering gear under the van It has a wire connector and 2 large EVAP hoses. look for any split or crack then follow the lines back to the tank. Even a small crack is a leak.

Hope helped with this. Remember rated this help. Good luck.

P0455 Evaporative Emission Control System Leak Detected (gross leak) - check your entire engine bay contents for any type of leak, air conditioner when it's running, coolant, things like that.

P1684 Battery Disconnected Within Last 50 Starts - this is a code that will go away over time

Hey, Code 0700-Transmission Control System (Malfunction Indicator Light Request)
Code 1684 -Battery disconnected during last 50 starts

Excuse i need information my car have the code P1193

P0442, P0455 AND P0456 are all evaporative leak monitor test failures (small, medium and large leaks). These codes appear anytime the integrity of the air space above the fuel or the lines to/from the vapor canister or purge valve. If there is no damage to the canister, check the lines that run under the van from the fuel tank and canister to the purge valve (under the hood). Also, check to make sure that the hoses are not split or disconnected where they connect to the purge valve. The P1684 is abit more confusing. This is not a valid DTC for your vehicle. It's possible the scanner the shop you went to is an OTC scanner that is reporting a false code. It's also possible they wrote it down incorrectly. The closest thing that makes any sense is a P1486 which would indicate a pinched hose in the same monitor system as the other 3 codes. Best of luck!