PCM\Chip question
Thread Starter
|
Senior Member
Joined: Dec 2001
Posts: 1,273
Likes: 0
PCM\Chip question
I just read Keggers blown motor thread. If mods will void the warranty, why does Ford put a port on the PCM for a chip? Does the port serve any additional function? Just curious.
Senior Member
Joined: Oct 2001
Posts: 978
Likes: 0
From: Windsor, Ontario, Canada
Q: Why did Ford add the connector to the end of the computer?
A: (Mike Troyer)
The whole idea behind those contacts, and the edge connector they are on, and that whole circuit, in fact, was so Ford could have a way of quickly testing different software revisions in their computers during new vehicle development, primarily.
You see, back when they originally designed the EEC-IV computer back in the early 80's, from day one they wanted their computer to be different from any other unit in the world. They didn't want the internal chip to be replaceable in any way, like it was in every other computer design at that time. GM, Bosch, etc., all used replaceable eproms. So they designed in this external alternate data path, as a manner of getting different software loads into the ECU, and made the internal eprom a surface-mount, so it wasn't replaceable in the normal manner. So at that time, using this external data path was the *only* way for many years to get a different program of any kind into the ECU. And as a result, for years Superchips was the only company in the world to be able to reprogram that type of computer. That was then, and this is now.
The end result is that it's still a very neat design, and chipmakers take advantage of it, by virtue of the fact that attaching to the edge connector turns off the factory eprom, and tells the computer to seek it's instructions externally. Removing the chip instantly restores the factory program.
So the actual *purpose* of those contacts was to allow communications between external data sources and the ECU, in an attempt to make their computers much harder to reprogram, and they succeeded for some time.
Beginning with the 1996 model year, they went to the EEC-V computer, which is a "flash" type of unit. Meaning it can be programmed either via the ALDL serial port up under the dash, which is how they do it at Ford dealerships when they have to update a factory calibration for some problem resolution, or via this external data path like performance chips do.
For Info , Click on Pic
My F150online Photo Gallery
Have a great day eh ! ......... Dave
A: (Mike Troyer)
The whole idea behind those contacts, and the edge connector they are on, and that whole circuit, in fact, was so Ford could have a way of quickly testing different software revisions in their computers during new vehicle development, primarily.
You see, back when they originally designed the EEC-IV computer back in the early 80's, from day one they wanted their computer to be different from any other unit in the world. They didn't want the internal chip to be replaceable in any way, like it was in every other computer design at that time. GM, Bosch, etc., all used replaceable eproms. So they designed in this external alternate data path, as a manner of getting different software loads into the ECU, and made the internal eprom a surface-mount, so it wasn't replaceable in the normal manner. So at that time, using this external data path was the *only* way for many years to get a different program of any kind into the ECU. And as a result, for years Superchips was the only company in the world to be able to reprogram that type of computer. That was then, and this is now.
The end result is that it's still a very neat design, and chipmakers take advantage of it, by virtue of the fact that attaching to the edge connector turns off the factory eprom, and tells the computer to seek it's instructions externally. Removing the chip instantly restores the factory program.
So the actual *purpose* of those contacts was to allow communications between external data sources and the ECU, in an attempt to make their computers much harder to reprogram, and they succeeded for some time.
Beginning with the 1996 model year, they went to the EEC-V computer, which is a "flash" type of unit. Meaning it can be programmed either via the ALDL serial port up under the dash, which is how they do it at Ford dealerships when they have to update a factory calibration for some problem resolution, or via this external data path like performance chips do.
For Info , Click on Pic
My F150online Photo Gallery
Have a great day eh ! ......... Dave