Hi,

I hope everyone is doing well. My little sister has been having issues with her 2011 Mazda 3 Hatchback. Where her car would have trouble starting; no crank. This is an intermittent issue where if she waited several hours it would start up again. However, this intermittent issue became permanent in March 2019.



Quick Timeline:

July 2017 – Purchased in San Francisco Bay Area

September 2017 – Sister moved to San Diego and issues started. Brought to a Mechanic A where they stated it was starter. Mechanic A replaced the starter however the issue continued. Brought the car to Mechanic B where they stated that the car was having communication issues with the cluster. The car’s cluster was replaced, and the keys were reprogramed. It was also noted by Mechanic B that only the Mazda dealer can reprogram the keys. After a few weeks her car was up and running without issue.

October 2018 – The intermittent starting issues came back after ~ a year. Issues continued through March 2019

November 2018 – Check engine light came on. Went to Autozone to check the code. It gave the code: U0100 which described the issue as the ignition on or with the engineering running the PCM detected a serial communications error. Check engine light went away on its own after a few days.

December 2018 – Car had trouble starting; Cranked. Replaced with a new battery. Car started again.

February 2019 – Discovered there was crack in one of her rims. This rim seemed to be repaired by the previous owner with JB-Weld. A use OEM rim was ordered and replaced on the Mazda 3.

March 2019 – Sister came out of class and her car did not start. Waited over 5 hours and it still did not start. She decided to have it towed to her apartment.

April 2019 – Search on the forums and it was noted that replacing the #20 and #21 40 Amp Fuses were reported to solve the issue. Changed the fuses but the issues continued.



To this day, the car does not start. No crank but all the lights and welcome message are functional. I’m trying to help my sister find a solution so that she can have a reliable source of transportation to school.

We tried reaching out to a locksmith, several mechanics and the dealer but unfortunately, they did not find a solution.

Any help would be very much appreciated!







Note: Red flashing lock and car icon on the cluster (Anti-theft) continues when we try to start the car

Suspected:

1. Immobilizer Issue

2. Faulty Key Fob

3. Temperature-Related

Summary of work done:

1. Replacement Starter (September 2017)

2. Reprogrammed Keys, replaced cluster (September 2017)

3. Replaced Battery (December 2018)

4. Discovered one of the rims were cracked and leaked. Replaced wheel and sensor (February 2019)

5. Towed to apartment as car did not start (March 2019)

6. Replaced #20 and #21 40amp fuses (April 2019)

 

Have you tried your spare key?

 

Hi,

Thank you for the response. Yes, I tried the spare key. I ended up taking the car to another dealership. They identified the root cause of the issue to be the faulty PCM. As it was indicated on the check engine light light code U0100. It was replaced under PZEV warranty free of charge. Car now starts! Hope this helps others in the future

Best,
AJ

 

Hey AJ, so I’m actually having this same exact problem right now with my 2010 MazdaSpeed3 and had a question for you. Did you take the vehicle to multiple dealerships before them finding out it was a faulty PCM? Because seeing that you’ve had to replace a few parts that maybe weren’t completely necessary to get since the problem was reoccurring, I just wanted to avoid doing all that since it might turn out to be a faulty PCM on my mazda as well. So please get back to me if you can as soon as possible! I’d love to see your point of view on this, thank you !

Daniel

 

1st thing to do is read the fault codes.

 

So as of right now the fault codes are throwing up U0155 and it’s throwing those up a few times. The code is for loss of communication with the cluster so seeing that AJ replaced the cluster and problems still occurred, I don’t want to replace the cluster if the people at the dealership think that’s the problem.

P.S. one other thing, I barely managed to turn on my vehicle two days ago when I switched the 15amp Meter fuse. It appeared to have been blown out so I replaced the fuse and car turned on, dials and everything else on dash weren’t lighting up or moving. Mileage didn’t show but radio and A/C did as well as headlights and tail lights. Whenever I turn off the car the fuse blows out once again.

 

U0155 is related to Climate A/C. U0155 : EATC ( electronic automatic temperature control )

 

I'm having a similar issue however if I turn the hedlights on, disconnect the battery and hold the terminals together for about 2 minutes, reconnect the battery and crank it; it turns over. This method doesn't always work on the first go usually 2nd or 3rd attempt. Haven't been able to get it scanned yet.

 

Hello folks.
I had the same issue with my 2013 Mazda 3. Turned out, we thought, to be a bad PMC. The PCM was replaced on my Mazda and the problem went away BUT only for a few months, ,maybe a year.
Now its happening all over again...………... but no fault codes.
Im not sure how the car could be burning through PMC's like that? there doesn't seem to be a short in any wires that I can see.( without tearing the car apart to inspect each and every wire). iv gone as far as taking out the tail lights and head lights to see if there was moisture in there somewhere,
I was forced to go buy a new vehicle.(NOT a Mazda) now there the car sits. waiting to be sold or scraped.
its like Mazda picked a few cars from every batch and installed something onto it to burn out the PCM.
Please update the forum is you find a possible culprit!

Frustrated and need help!

 

My issue just went away. Still not sure what the issue was. Didn't bother to get it scanned. I think it could be an issue with the wiring as I read that they are mostly aluminum not copper so they tend to break.