Thread: Trans Bangs Into 1st-P1573

Soo for those of you not familiar, the trans will randomly bang into first gear from a stand still, almost like it fails to engage at first, when you lightly ease into the throttle. Well. I went to a reputable trans shop and they ran a diagnostics test on it and found code P1573-PCM/EBTCM Serial Data Problem. He mentioned the problem was with the line pressure.
According to google it means that connection was lost between PCM and EBTCM (electronic brake/traction control module).

Soo. Yay for not needing a rebuild!

But now what?? They suggested that I go to "Redwine Automotive" here in Memphis, says they are the best when it comes to electrical problems. He said there were no loose or frayed wires, which I am going to go back over anyway. Sooo I'm not sure what to do.

I tell you what. I'm sorta confused what the EBTCM (EBCM whatever) has to do with transmission line pressure.
If you guys recall, I DID have my EBCM rebuilt, and I DO NOT have any trouble lights on, no CELs, no ABS/TCS lights, nothing. So I'm just confused.

What should I do? Can't have it slamming in first no matter how few and far between it does it, surely it can't be good for it.

Thanks guys! As always any and all help is greatly appreciated! Cookies will be given

From what i know i believe data is sent to a line pressure regualtor that controls how much line pressure to let through. My guess is a bad wire harness or a melted wire somewhere. Just my opinion

Thanks Bryant! I'm going to first call modulemaster and see if they know anything about it or want me to send my ebcm back to them.
Second we're gonna take it and get the wires looked through if I don't find it.
And lastly replace the EBCM.

Someone on GPONA had a service dvd from GM or something. You can read it all in here. Grand Prixs Of North America • View topic - P1573

Well. This problem is apparently very intermittent and has come back this past week. Aeroforce isn't even plugged in so I guess it's not walking over communication? IDK. Still have P1573 popping up, which according to GM service manual, Billboost, and TON, the code does not exist on a 2003.

The point is. Grand Prixs Of North America • View topic - P1573 THIS, from GM, suggests wiring, PCM, or EBCM. Wiring has been checked and tested for resistance and is fine, EBCM was rebuilt of course, soo before I consider transmission as a potential problem, figured what the hell let's replace the PCM. Hell it even suggests PCM replacement before anything anyway.
I know most say it's robust and bullet proof and blah blah...but I have heard of cases where the PCM causes problems so it's worth a shot.
I just find it hard to believe the transmission has a problem. It went months without the problem and then poof it returns. That sounds more electrical than anything.

1. With that being said... "remanufactured"...this is a "stock PCM". Do they all say that or is there more to it? Somethin tells me this is why P1573 exists on my car when it shouldn't because it's an 03. And perhaps there's more to the story...


2. Also, if I'm gonna replace it, I know Nix will have to re-tune me but that's fine I have a 3.8 I can roll around with. But Car-Part lists multiple vehicles with the same part number. Soo does the PCM have to be a 2003 GTP or will another one work??

3. And lastly, will HPT be able to change VIN and bin file (and vcm ID) if I change PCM's and make it work for my car and HPT tuning?

What Chris suggested is just get a canned tune, instead of a junkyard one. That way all my stuff is prgrammed on it and it'll drop right in. And perhaps not have to buy credits? And if the PCM is not the cause, a canned tune is marketable as well.

**Update

Well, Matt and I got to talking. And the PCM I have in my vehicle is part # 12209624. Again, it says remanufactured. I'm going to go to the dealer tomorrow and get service history and find out if they did it so I can lulz.

But anyway, the part # required for my car is 12583826.

The list of cars this PCM fits ONLY is:
2003 Bonneville (all engines)
2003 Grand Prix (n/a and SC 3800)
2003 Impala / Monte Carlo (n/a and SC 3800)
2003 LeSabre (all engines)
2003-04 Park Avenue (all engines)
2003-04 Regal (all engines)

So some idiot put the wrong PCM in my car. That's great... But anyway, I'll report back on how this plays out.

If you look up your number in the GM database, it likely comes back as an early 03. Then various revisions etc bring you to what Matt told you. Likely.... An 03 only works with the right pcm because they are a bastard year. Your intermittent isn't because of a wrong pcm. Your intermittent might be due to a flaky pcm. Which..saying reman on it..I'd swap a pcm in. Just read what you have on that pcm and transfer it onto another 03 pcm. The glitch is likely a bad chip inside the pcm.... not a programming issue. Then you have all the same crap on a different pcm.

In diagnosing my trans issue..I grabbed a spare 98-02 pcm off the shelf and programmed it up. When I went to put it into the car, I found the service number etc was identical to the one I pulled. Odd...I figured I had probably grabbed a Lumina pcm or such.

Lol yeah I know that's right. Honestly, I'm not sure HOW to put the proper PCM in the car... I mean I have a part # and a barcode to go off of on that reman. It doesn't have all the info. like the stock ones do.

I was talkin to Brian last night, and it ran across my mind that the aeroforce gauge went out and the trans did it's thing again simultaneously. So he suggested checking all the grounds. And then instead of tossing a PCM at it and not knowing, and since this car has a history of electrical gremlins (bad ebcm and what not) that it might be worth having the dealer diagnose it using their TechII and what not. At least then I'd know what's going on...