Will not start, codes U0100, P2101, P0113

CARRIE MAE

MEMBER
2010 MAZDA 3
2.0L
4 CYL
2WD
AUTOMATIC
151,000 MILES

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?

2 Replies

CARRIE MAE

MEMBER
3 POSTS

Anyone have any ideas? Kind of need my car.

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Wednesday, April 21st, 2021 AT 11:06 AM

KASEKENNY

MECHANIC
18,907 POSTS

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.

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