Hey Gang:

Recently got the code P2229 on our new "used" 2007 CX-7. It refers to a faulty Barometric Pressure Sensor in the engine. BIG Thanks to Grim who shared that it is part of ( inside ) The PCM/ECM. ( Powertrain Control Module & Engine Control Module ) Research has told me this is essentially the engine's BRAIN. I'm finding new parts on the web for around $225, and we were told that even a used part may do the trick. I've found them around $120. Here are the TWO challenges, or questions I face.

1) These need to be programmed "specifically" for each car according to its VIN. Only the new parts seem to be selling pre-programmed? So, is programming a used PCM something most any good Mechanic shop can do?

2) The second and more confusing issue is that there are many different part numbers for this part. I don't mean extremely different, I mean "just the last number" in the part number sequence? For example, if you look at the link below from a high rated ebay shop, you see the same exact part with that one different last number?

https://www.ebay.com/itm/2007-07-MAZ...gAAOSwncFb34Ww

Its like 881G, 881H, 881L, 881R, etc. Does anyone know how I would find out this number for my specific vehicle without having someone actually pull the part? This is definitely a part you don't want to make a mistake on!

Thanks for ANY help or guidance, Tom

 

The letter at the end, "G" would be a older version PCM, and ist the suffix for supercessions, ***881R would be a later version of the PCM.

What is the number/numbers on your original PCM?

 

If you are friendly with the the parts department at Mazda, you can give them your vin/chassis number, get the PCM part number listed for your vehicle, then ask them to look at the old supersession numbers and compare your ebay search.

 

As far as your first question.
i don't think any "any good Mechanic shop" can do that. The PCM reprogramming is tricky and lots of times you cant reuse the PCM because they are vin locked. Technically dealers cant reprogram the vin, but... some other things are possible like replacing memory in the PCM.
As far as Mazda cars it is possible to install the used PCM and the engine would run as those cars have an immo in their dash.

You have a few options as far as the used PCM. You can post your question on the different forums; like digital kaos and forscan.
Or since it looks like you are located in USA, and you could search for used pcm in car-parts.com or used local u-pull it yard. Get a cheap unit and try that.

 

Mazda dealers can reprogram used PCMs to your vehicle. They wipe it and reprogram your VIN number & vehicle info into it.

 

My computer has been down for a few days, so Thank You both for your help! Unfortunately grim, I don't know the number on my current PCM? Its actually my girlfriend's car, and the PCM is still in the vehicle. I'm legally blind and certainly no mechanic, so I can't pull it myself!

If the last letter of the part number has to do with being the latest version, should I not just go for an 881R for example? OR... does the last letter "have to" be the same as the current PCM. You've been a big help. So again, thank you!

 

I'm not 100% sure on if all supersessions will fit your vehicle.


QUOTE If you are friendly with the the parts department at Mazda, you can give them your vin/chassis number, get the PCM part number listed for your vehicle, then ask them to look at the old supersession numbers and compare your ebay search.

 

Here’s an FYI for anyone with a similar problem, but first, another HUGE thank you to grim_reaper who has provided a great education about the PCM / ECM /ECU! Especially since I had NO clue about what a supersession was. Here’s what I was told by the Parts Department at our local Mazda dealer.

First, the PCM/ECM part number for my personal 2007 CX-7 is this “L33L-18-881H”. ( keep those last 3 numbers and last letter in mind ) As grim mentioned earlier in this thread, they kept updating the part, but the only thing that changed about the part number was the last letter. So your vehicle could have and 881G, 881H, 881R, etc. You get the point.

I didn’t even have to pull the part. The dealer was happy to provide the correct number for MY vehicle by simply providing my VIN. He also said they generally refer to it as the ECM rather than the PCM.

My original problem was the vehicle showing the code P2229. This refers to a bad “Barometric Pressure Sensor”. ( which is inside the PCM ) The dealer told me that they no longer call this a barometric pressure sensor, and they now refer to it as a “Boost Sensor”! It’s the sensor that determines the proper mixture of gas and oxygen for your vehicle to run at optimal capacity.

Anyway, he also said he doesn’t think Mazda even makes any of these older parts now. They only make a Boost Sensor whose part number ends in 881U. I did a bit of research to find a new ECM and they ranged between $600-$950. However, he said I could put a used 881H into the vehicle and they would program it for me.
( NOTE: These parts are programmed specifically for your VIN ) So don’t just let any “joe mechanic” install it if they don’t know this !

The average price for a used PCM/ECM was around $225. You may find one cheaper, but that would likely be an older one. If it’s a used part, there’s no telling what condition any of the other sensors are in. That said, I live paycheck to paycheck, so I have to take the chance on a $225 part.
If you shop carefully, you may just fix any PCM/ECM issue much cheaper.

I hope this all might help someone else down the road. Grim paid it forward to me, so I’m trying to do the same for anyone else?

Good Luck!
tomroe1