Will not start, codes U0100, P2101, P0113

2010 MAZDA 3
151,000 MILES • 2.0L • 4 CYL • 2WD • AUTOMATIC
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CARRIE MAE
  • MEMBER
  • 3 POSTS
I bought vehicle and noticed major suspension problems. I put almost a whole new front end on it to finally figure out it was a bad transmission mount. I changed it and the car ran beautifully for about 2 days. While driving i noticed my engine light flashing. Stopped and turned car off for about an hour and it went away. The next day while driving engine starts to decrease In RPMs and sounds awful. Wouldn't go over 40 MPH. Replaced the battery, starter, MAF sensor, Absolute pressure sensor, checked and replaced all fuses, replaced burnt battery terminal fuse. Cranks, clicks a lot. Wont start. Codes U0100, P2101, P0113, and cylinders 2 and 4 are misfiring. I have checked all grounds, relays, and made sure all connections are correctly in place. What else could be wrong with it?
Apr 20, 2021 at 12:58 AM
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CARRIE MAE
  • MEMBER
  • 3 POSTS
Anyone have any ideas? Kind of need my car...
Apr 21, 2021 at 11:06 AM
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KASEKENNY
  • ASE Certified Mechanic
  • 18,907 POSTS
  • ASE Certified Mechanic
If the engine is not starting then we need to start with the P2101.

https://youtu.be/dCjmRL3p4Cs

This main relay is going to directly cause a no start so basically the PCM is not seeing proper voltage and it takes the voltage away.

Does this happen all the time? If not, then we need to start with this and go from there.

Sounds like the misfiring is a different issue so let's start with the testing below and go from there.
Apr 21, 2021 at 4:13 PM
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