tuner and PCM
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Legend
Joined: Feb 2005
Posts: 8,058
Likes: 183
From: Fort Worth, TX
tuner and PCM
I find it ironic that my PCM went out 6 weeks after I put the SCT tuner from hemifever on it. Sean says it shouldn't have killed it, but Ryan at All Computer Resources says that a tuner strains the PCM CPU a little more, which could have caused to the failure.
He says that SCT'ing the replacement/re-man PCM will void their lifetime warranty because it overwrites their default programming, but he won't tell me what it would damage in the PCM, other than that above.
$225 shipped, they had trouble getting a good unit so they over-nighted it for free. plug it in, and everything was happy and grand.
He says that SCT'ing the replacement/re-man PCM will void their lifetime warranty because it overwrites their default programming, but he won't tell me what it would damage in the PCM, other than that above.
$225 shipped, they had trouble getting a good unit so they over-nighted it for free. plug it in, and everything was happy and grand.
Thread Starter
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Legend
Joined: Feb 2005
Posts: 8,058
Likes: 183
From: Fort Worth, TX
Still trying to make a connection between tuner and failure.
This is the all-but-argument I've been having with ryan at ACR. I don't care about the tuner voiding the warranty (generally, a lifetime warranty means it shouldn't fail), but I'm trying to get down to the bottom of things- Did the tuner have a direct impact on the PCM failing.
I understand him being tight lipped about things, but he could at least answer my questions instead of being anally CYA.
I know the "No Bus" message comes up 3 times when tuning.
I just forwarded the whole string of emails to Sean (hemifever) for his input.
Strangely (or maybe not so much), There's no way to actually call this character. The phone number goes to a call center, and he only answers his email once a day, around 9-10AM.
Ryan Decker rdecker@allcomputerresources.com
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Ryan,
Computer works great.
Question:
Other than the whole warranty thing, what negative effects would having a tuner have on the PCM?
Hemifever, the SCT tuner, says that the tuner should not have contributed to the PCM failure. I installed the 93 octane tune (which picked me up 2 MPG and 35 HP on the dyno, not bad for a V6) about 6 weeks before the PCM failed. That was the only computer modification I've made to the truck. Just seems kind of fishy to me.
I've read that the checksum error is basically caused by one of two things: 1) the RAM modules, like those for a desktop, finally have a silicon bridge break inside an IC chip due to vibration, ect, and 2) a high voltage spike as a result of a ignition coil going bad or otherwise strong EMI in the area of the PCM
What is your definition of a "checksum error"?
- Steve
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Tuner will add more strain to the PCM and vehicle itself. I personally use one since I’m not concerned about that. The company policy is no replacements for PCM that are tuned since you will basically override our programming.
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Ryan,
Which tuner do you use, SCT, Jet, or SuperChips?I went with SCT since they are individually programmed based on the sniffer results on a dyno.
It picked me up 1/2 a second in the 1/8 mile and +5 MPH. And picked up 2 on the mileage as well.
What exactly is the definition of the Checksum error? Is it just a matter of removing the damaged RAM that Dodge used, and replacing it with Texas Instruments chips?
I understand knocking out the warranty for obvious reasons. I just want to make sure the tuner didn't cause the PCM to die.
- Steve
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I use SuperChips. I cannot get in to too much details about the Checksum and RAM. Checksum is basically loss of communication more than 7 times.
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Ryan,
"Checksum is basically loss of communication more than 7 times."
Loss of communication with what? Just no bus communication to the CTM/dash/other modules, or loss of communication between the CPU and RAM, or ???
A big company would be saying "Yes, plug your tuner in, void the waranty and buy another PCM from us again!".
I can't really tell what you're saying, whether to not use it at all because it will damage the CPU/RAM, or that there shouldn't be any hard effects until years down the road.
- Steve
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Steve,
Our company policy indicates that tuning your PCM will void the warranty.
================================================== ====
Ryan,
I understand that.
But what items lose communication 7 times, as you describe, to cause a checksum error?
How does a tuner invoke more load on the PCM, if all it does is modify the fuel and timing curves? Changing a PWM here and a sensor base value there, surely can't cause a huge havoc to occur.
- Steve
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Mr. McDermott,
Simply the tuner will override our programming. This is why it voids the warranty.
I cannot specify the exact components on the printed circuit that cause the failure as it has taken us many long nights to figure that our ourselves. These would be considered monetary inventory. Thanks for understanding.
================================================== ====
Ryan,
So what correlation would it have been for my PCM to go out only 4 weeks after having put a tuner on it? I can't see as having inflicted extra load on the PCM, since all it does is adjust the maps, but the "No Bus" error that the tuner invokes as part of the programming process is what makes me curious when you say a checksum error is "a break in communication more than 7 times".
- Steve
================================================== ====
This is the all-but-argument I've been having with ryan at ACR. I don't care about the tuner voiding the warranty (generally, a lifetime warranty means it shouldn't fail), but I'm trying to get down to the bottom of things- Did the tuner have a direct impact on the PCM failing.
I understand him being tight lipped about things, but he could at least answer my questions instead of being anally CYA.
I know the "No Bus" message comes up 3 times when tuning.
I just forwarded the whole string of emails to Sean (hemifever) for his input.
Strangely (or maybe not so much), There's no way to actually call this character. The phone number goes to a call center, and he only answers his email once a day, around 9-10AM.
Ryan Decker rdecker@allcomputerresources.com
================================================== ====
Ryan,
Computer works great.
Question:
Other than the whole warranty thing, what negative effects would having a tuner have on the PCM?
Hemifever, the SCT tuner, says that the tuner should not have contributed to the PCM failure. I installed the 93 octane tune (which picked me up 2 MPG and 35 HP on the dyno, not bad for a V6) about 6 weeks before the PCM failed. That was the only computer modification I've made to the truck. Just seems kind of fishy to me.
I've read that the checksum error is basically caused by one of two things: 1) the RAM modules, like those for a desktop, finally have a silicon bridge break inside an IC chip due to vibration, ect, and 2) a high voltage spike as a result of a ignition coil going bad or otherwise strong EMI in the area of the PCM
What is your definition of a "checksum error"?
- Steve
================================================== ====
Tuner will add more strain to the PCM and vehicle itself. I personally use one since I’m not concerned about that. The company policy is no replacements for PCM that are tuned since you will basically override our programming.
================================================== ====
Ryan,
Which tuner do you use, SCT, Jet, or SuperChips?I went with SCT since they are individually programmed based on the sniffer results on a dyno.
It picked me up 1/2 a second in the 1/8 mile and +5 MPH. And picked up 2 on the mileage as well.
What exactly is the definition of the Checksum error? Is it just a matter of removing the damaged RAM that Dodge used, and replacing it with Texas Instruments chips?
I understand knocking out the warranty for obvious reasons. I just want to make sure the tuner didn't cause the PCM to die.
- Steve
================================================== ====
I use SuperChips. I cannot get in to too much details about the Checksum and RAM. Checksum is basically loss of communication more than 7 times.
================================================== ====
Ryan,
"Checksum is basically loss of communication more than 7 times."
Loss of communication with what? Just no bus communication to the CTM/dash/other modules, or loss of communication between the CPU and RAM, or ???
A big company would be saying "Yes, plug your tuner in, void the waranty and buy another PCM from us again!".
I can't really tell what you're saying, whether to not use it at all because it will damage the CPU/RAM, or that there shouldn't be any hard effects until years down the road.
- Steve
================================================== ====
Steve,
Our company policy indicates that tuning your PCM will void the warranty.
================================================== ====
Ryan,
I understand that.
But what items lose communication 7 times, as you describe, to cause a checksum error?
How does a tuner invoke more load on the PCM, if all it does is modify the fuel and timing curves? Changing a PWM here and a sensor base value there, surely can't cause a huge havoc to occur.
- Steve
================================================== ====
Mr. McDermott,
Simply the tuner will override our programming. This is why it voids the warranty.
I cannot specify the exact components on the printed circuit that cause the failure as it has taken us many long nights to figure that our ourselves. These would be considered monetary inventory. Thanks for understanding.
================================================== ====
Ryan,
So what correlation would it have been for my PCM to go out only 4 weeks after having put a tuner on it? I can't see as having inflicted extra load on the PCM, since all it does is adjust the maps, but the "No Bus" error that the tuner invokes as part of the programming process is what makes me curious when you say a checksum error is "a break in communication more than 7 times".
- Steve
================================================== ====
Maybe its just me but I dont see how using a sct would cause a strain on the computer. All it does is rewrite the memory that the computer already knows. I kinda look at it this way its like jail breaking a iphone you still have the same product and it does all the same things but it allows you to get more potential from it. Maybe comparing a pcm to a iphone isnt correct but I cant currently think of what else to compare it too lol. Ive had my sct for 4 months on the 93 tune and its been great!
Thread Starter
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Legend
Joined: Feb 2005
Posts: 8,058
Likes: 183
From: Fort Worth, TX
Maybe its just me but I dont see how using a sct would cause a strain on the computer. All it does is rewrite the memory that the computer already knows. I kinda look at it this way its like jail breaking a iphone you still have the same product and it does all the same things but it allows you to get more potential from it. Maybe comparing a pcm to a iphone isnt correct but I cant currently think of what else to compare it too lol. Ive had my sct for 4 months on the 93 tune and its been great!
I would imagine I'd be fine to hit it with the SCT, but this character is being so CYA about it, it's like he programs them to not be programmable or something and just wants be to not have to buy another unit or something.
Very fishy. But I don't want to program it and get stuck again.
He won't give me a clear and dry cut as to what the checksum error means, either. In computing, it basically means a bad RAM module. Replace RAM module, all is fine. PCM has the RAM onboard, so that's why it has to be remanned. But I don't know if the PCM is like a computer in that respect or not.
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Thread Starter
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Legend
Joined: Feb 2005
Posts: 8,058
Likes: 183
From: Fort Worth, TX
Here is Hemifever's response:
I can't recall all our conversations but did you get a recovery file from SCT to load in to the pcm? That generally helps when folks kick the cable off during tuning or the tuner loses contact to the pcm while tuning. I would expect it to work for you.
But...to answer your question....the tuner writing to the pcm is 100% the same as you going to the dealership and them hooking up their equipment to the odb port and flashing the pcm. No difference. Tuners have been programming pcm's since the late 80's.
Saying that, I do have a bunch of dodge folks emailing me with p0601 error pcm's due to failure (age related usually) and ask if I can flash them to fix it. Sometimes it actually works. Excessive heat can deteriorate the pcm too like from headers.
yes, a checksum error is a data/program mix match. The pcm is a set of complex tables in a 3d type of cube. A big program written into a ROM on a chip. If you're familiar with computers, there is an md5 checksum value with a file. If you copy that file from one computer to another, the checksum should match. If something happened during the copy it would fault out with a checksum error. So it's the same thing on a pcm. Your pcm may have truely failed out of coincidence. You could call SCT and tell them you were swapping tunes like you do here and there and after it tuned successfully it failed to start. Tell them it started for like 5 seconds and then cut off. Ask if they can try a recovery file before you get a new pcm. They will need you to be at your desktop pc with the tuner and know your pcm part number. They can put the tuner in recovery mode. Then the tuner will try to forcefeed the pcm the stock program. If the pcm is bad, this process will fail no doubt.
But...to answer your question....the tuner writing to the pcm is 100% the same as you going to the dealership and them hooking up their equipment to the odb port and flashing the pcm. No difference. Tuners have been programming pcm's since the late 80's.
Saying that, I do have a bunch of dodge folks emailing me with p0601 error pcm's due to failure (age related usually) and ask if I can flash them to fix it. Sometimes it actually works. Excessive heat can deteriorate the pcm too like from headers.
yes, a checksum error is a data/program mix match. The pcm is a set of complex tables in a 3d type of cube. A big program written into a ROM on a chip. If you're familiar with computers, there is an md5 checksum value with a file. If you copy that file from one computer to another, the checksum should match. If something happened during the copy it would fault out with a checksum error. So it's the same thing on a pcm. Your pcm may have truely failed out of coincidence. You could call SCT and tell them you were swapping tunes like you do here and there and after it tuned successfully it failed to start. Tell them it started for like 5 seconds and then cut off. Ask if they can try a recovery file before you get a new pcm. They will need you to be at your desktop pc with the tuner and know your pcm part number. They can put the tuner in recovery mode. Then the tuner will try to forcefeed the pcm the stock program. If the pcm is bad, this process will fail no doubt.
Last edited by magnethead; Sep 28, 2011 at 01:16 PM.
Thread Starter
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Legend
Joined: Feb 2005
Posts: 8,058
Likes: 183
From: Fort Worth, TX
Character is being...well, a character.
I sent him what Hemifever had to say.
His reply:
"Sounds like he has a programming issue that needs to be looked at if his tuners are causing so many problems. I am not sure on the rest. I would not advise to tuning the PCM. Tuning the PCM will void the warranty."
My reply:
I sent him what Hemifever had to say.
His reply:
"Sounds like he has a programming issue that needs to be looked at if his tuners are causing so many problems. I am not sure on the rest. I would not advise to tuning the PCM. Tuning the PCM will void the warranty."
My reply:
If you give a lifetime warranty, isn't that usually a pretty good sign that you design them to not fail? Or do you have it programmed to catch fire and break into 1000 pieces when tuner is plugged in?
Just sayin.
Just sayin.
Champion
Joined: Jul 2011
Posts: 4,895
Likes: 35
From: Gilbert, Arizona
open one and look how fun
I know computers fairly well I’m no programmer NO but it would be interesting to see inside one of these.
1. The quality of components
2. Quality of layout
3. It would be nice to reprogram them yourself with just a laptop
4. I have always wondered why this is not inside the car not outside in the super-hot engine compartment in the humidity and freezing cold you would think it should be inside the car.
1. The quality of components
2. Quality of layout
3. It would be nice to reprogram them yourself with just a laptop
4. I have always wondered why this is not inside the car not outside in the super-hot engine compartment in the humidity and freezing cold you would think it should be inside the car.