Hi!

Some prior info first. The car is a 2005 with a rebuilt motor. The center console lights went out/ lost function and was left in the hands of an electrical engineer. 12 volts was put to the 5v barometric pressure sensor line and the PCM/ECU was fried. A new PCM was purchased to match the codes to the one in the car. Everything was swapped and I cannot seem to see or find anything else electrically wrong with the car. Since then, I have repaired the center console lights and will be making a quick DIY for it as I have searched and found others that have had the same problem.

Ive done some searching and there are a lot of threads about this crank problem but none seem to tell me anything definitive aside from the fact that I HAVE to take it to the dealership to get the new PCM programmed to the keys that I have with the car. That I know and I definitely dread.

What I am curious about is with a PCM that doesnt have matching the keys, will the car crank at all?
In my case, the car doesnt crank at all. But what makes me scratch my head is that all the aux/accessory relays click off when the key is turned to the start position as if the car WANTS to crank, but alas nothing happens. Dash, center console, a/c etc power down when the key is turned to the start position. I have even asked someone to turn the key to the start position as I jumped the starter itself. The engine DOES crank that way, but doesnt start. I am assuming its because the PCM isnt telling the injectors to inject fuel. I dont have much experience with PCMs that need specific programmed keys, so this is new to me.

Is whats happening with the car accurate to what should be happening? Or do I have a more severe electrical problem?

Lastly, to those who are more experienced in dealing with a dealership to get keys programmed to the PCM, what should I expect when I haul the car there? Any questions I need to ask or know about when I step in?

I know that I need to have the ECU to "as built" data.
I know that iDs software is used (and have attempted already with my Ford mechanic friends but was halted when it came to inputting some data that was specific with Mazda's information. But supposedly, he was able to get the PCM to the as built data. He told me the PCM is updated to this specific car. Can anyone else educate me with this?)

I worry that I go through the effort of hauling the car there and they cant guarantee me that the car will start... sigh...

Thanks for the help in advance! I know its a lot of questions! haha

 

Someone with more knowledge will chime in I'm sure, but looks like you have fallen victim to the immobilizer bit. Basically the theft deterent mechanism. The dealer is your only answer, with the exception of an '04 ECU that has been reprogrammed by Racing Beat and the bit turned off. I happen to have one of those, but you can't have a CAT when using it as it has a race flash on it.

 

if no security light flashing then it is not an immobilizer.
If the oem pcm was replaced ( why did it need replacing?) then there is no other choice to take it to the dealer for programming. The can bus system has to allow all the sensors to talk to each other and then to the pcm before the pcm will allow a crank condition to engage.
Mazda has propiertary pass words etc to get the appropiate build data entered and secured with the pcm and key functions. I hate this type system too--but it is what it is.
Are you getting a cel light when the ignition is turned to start?

 

somewhere there was a DIY on key programming... Would that help?

 

not in this case.
OD

 

The procedure to reprogram needs to be perfect...and a bit of voodoo luck as well.

It took 3 tries to get mine re-programmed when it crapped out

 

You need the following to get the PCM to work

- As-built data from Mazda
- PATS information
- a "pass-thru" device that is J2534 compatible

You can get the data from Mazda for a small fee but the pass thru device will cost you an arm and leg (over 1.4K)

so your best is just tow your car to dealership and tell them to do everything for you, probably gonna charge you 1-2 hours of labor but its much cheaper than the stuff above.

I got my As-built data and PATS info already so if something goes wrong, I can go to any shop that has a J2534 device, download the newest calibration and do everything there (or myself)

I was thinking of getting the device myself cuz most of the car these days works with it, but I just bought a Rotary compression tester and that thing cost a load. so I guess I'll wait for a while.

 

Doh! Forgot to talk about the CELs and the light I dont recognize.
Currently, there are no CELs. But, I think thats becuase the car hasnt been running at all so I doubt the PCM has recognized any check engine problems. But I know for sure there will be a CEL because even if the car keys start the car, the keyless isnt programmed to the car, thus CEL.

The other dash light that I dont recognize, which I now assume is the immobilizer is a light that looks like a key. Common sense tells me that its the Immobilizer check light, but common sense also told me that rotories work lol. So if someone could confirm that the key looking light is the Immobilizer, I would appreciate it. I cant seem to find a picture of it listed on the site and I dont have a factory manual for the car.

Thanks for all the input everyone! I think I just need to find a good Mazda Tech that is willing to actually put in the effort to really make it work and get it started.

I believe the as built data is loaded. The PATs information, is that a series of numbers and letters? When my friend was working at getting it started with the iDs software, he told me to write down a sequence of numbers and letters. Is this information important to have along with me when I get into the dealership?

Thanks again everyone!!!

 

We need an redundant array of PCMs...

 

^Project.... it looks like below. Your key and the ECU have to match codes or the car simply will not start. The key will fit, turn, etc, but the car itself will not work as the ECU doesn't know the key's code and so says "uuh-uh, no way".

 

Spin, Thanks for posting that.

That is definitely the light thats being lit.

Lets hope dealership can work it out, sigh.

 

2 things.
1- That light that is blinking--let it blink for a minute or two. It will be blinking very rapidly. But after that it will stop and give a random series of blinks. That will be a code. I will be willing to bet it will be code 1-6 which is no communication between keyless modules and pcm.
2- if you do not have a cel when you 1st turn the key to start, it is my understanding that means no power to the pcm.
I am struggling with the same issue on an S2 model right now. My OB2 port will not allow any communication with the pcm .
I havent had time to finally figue this out as I am trying to get my Pettit engine into my other car, its Prom week, work my job, Mother day week and I am drowning in estrogen.--sigh.
OD