P0201,p0202,p0203 - 2003 Hyundai Accent

Where are you located ? US service repair info. shows this vehicle as being built 2012 to 2016

Try this website. Scroll the boxes at the top of the page and click find, it will list most codes including some of the maker specific ones.
http://obdii.pro/en/code/P1215

the causes of the codes are --wiring---injectors--- ECM
unless you have a wiring loom connector disconnected say at the ECM or at the engine loom for the injectors ,I would suggest replacing the ecm with a known good one as the common failure point is the ECM

I would try disconnecting battery again. Disconnect both cables and touch them together for a few seconds. This will reset all modules. Wierd that you had so many codes after just disconnecting battery. Sometimes very hard to tell if ecm is bad.

How do I fix code po201 po202 po203 po204 on 2006 pt cruiser

I will give you what the codes mean and you can then work out what to replace.
code p0171 refers to system too lean--bank 1===causes intake / exhaust leak---AIR system---MAF/VAF sensor---fuel pressure/pump---injector/s---HO2s
code p0201 refers to injector 1--circuit malfunction===causes--- wiring--injector ---ECM
code p0202 refers to injector 2 --circuit malfunction===causes --wiring---injector--ECM
code p0203efers to injector 3 --circuit malfunction===causes---wiring--- injector --ECM
code p0204 refers to injector 4 --circuit malfunction===causes ---wiring ---injector ---ECM
code po321 refers to crank shaft position (CKP) sensor/engine speed (RPM) sensor---range / performance problem===causes---air gap---metal particle contamination---insecure sensor /rotor --wiring---CKP/RPM sensor.

Recommend replace CKP (crank shaft position) sensor 1st, clear codes and recheck.

Hate to say it but it could probably be you PCM.

I think you should go for manual first after that it would be easy for you to solve your problem. I had visited this site past 2 months before for my vehicle and find it quite helpful may be you will also get something useful here
Dodge Dakota

CODE 27 - Injector Control Circuit, output driver does not respond properly to the control signal

Code 27 MIL light options: OBDII
P0201 - Injector #1 Control Circuit
P0202 - Injector #2 Control Circuit
P0203 - Injector #3 Control Circuit
P0204 - Injector #4 Control Circuit
P0205 - Injector #5 Control Circuit
P0206 - Injector #6 Control Circuit

CODE 43 - Cylinder Misfire, or Ignition Primary Circuit

CODE $# MIL options: OBDII
P0300 - Multiple Cylinder Misfire
P0301 - Cylinder #1 Misfire
P0302 - Cylinder #2 Misfire
P0303 - Cylinder #3 Misfire
P0304 - Cylinder #4 Misfire
P0305 - Cylinder #5 Misfire
P0306 - Cylinder #6 Misfire
P0351 - Ignition Coil #1 Primary Circuit
P0352 - Ignition Coil #2 Primary Circuit
P0353 - Ignition Coil #3 Primary Circuit