Factory ECU programming

[Pyro15D]

I just had a little question. How are factory ECU's programmed? Like pre-OBD and now? I was just thinking that for the most part, ECUs are made by a third party manufacturer (Denso, Bosch, Delco) and arrive at the factory already assembled. Are they programmed beforehand by the ECU manufacturer, or are they programmed in the assembly line by the automobile manufacturer? Not that it really affects me, my curiosity is purely academic. I was just thinking about it on my drive to work this morning.

 

[toyotanos]

Chips were burned with the programs at the factory and either soldered onto the board or installed into sockets on the main board.

Unlike their modern counterparts, you weren't able to 'flash' the chips with different programs easily. IIRC, you could re-burn them, but that's beyond my experience.

 

[Pyro15D]

That's what I thought but I wasn't 100% sure. So what you're saying is the older pre-OBD ECU's were programmed with some sort of gang EEPROM programmer then soldered in afterwards. Are the new OBD-II ECU's programmed via the OBD-II port or is there some specialty port on the board reserved for that?

 

[toyotanos]

I can only speak for Toyota, 'cause that's where I work, but ODB2 port/DLC3 is the access point to the vehicle computer system for sure. Diagnostics, codes, data lists, reflashes, everything goes through that port.

Never saw old chips' manufacturing, so I can't say exactly how they were done, but I know it was more or less a 1-way street, as you didn't reflash them, they just replace the entire box.

 

[Pyro15D]

You work for Toyota? Awesome! That being said, with the newer ones (2005 Tundra for example), does Toyota have software that lets you 'tune' the engine or transmission, or is it more of a reflash-only sort of deal where you only can choose from a specific list of maps? I suppose I could just start a thread over on the Tundra Solutions forum, but this board seems to embrace "beyond the book thinking" more than the other forum. That's why I like you guys!

 

[3p141592654]

The Supra era (including mk4) ECUs are programmed at the chip foundry and cannot be changed. In other words, a set of photo masks are used to define the top metal layers of the chip and set the values of the ROM memory. They cannot be changed after that. The software version is actually printed on the chip if you know where to look. That meant the code better be correct, or you just squandered a couple million bucks on a useless chip run.

Today half baked stuff can go out and be reprogrammed in the field thanks to FLASH memory. Volvo has been a leader in the new wave. Even back in 99 Volvo had a master server at the factory that kept track of all software loads on every car they made. You hooked up their VADIS system to the car, and over the internet it would download the latest software versions. The sophistication of that system was a major reason for Ford buying them back then.

 

[Pyro15D]

I had no idea they went that far into it. I wonder how many people they had double checking the code to make sure it was right! My father was an electrical engineer at SGS-Thompson (now ST) and he used to tell me all about drawing up the chips and how they etched the silicon to make the various circuits in there (I actually got to tour the FAB in Milan as well :icon_bigg). It seems like programming is far easier today than it was back in the 80's and 90's.

The way I'm understanding you on the new software is they can flash the program to the ECU but are we able to get in there and 'mess' with stuff? I know Mitsubishi, Subaru, and GM have been very kind letting us have access to their maps and such, but the general consensus that I've heard is that Toyota still has things locked down pretty good. Is it a matter of the language they use to program the ECU? I mean, it doesn't seem to be too tough to just reflash a factory tune to the newer ECU's but actually opening up the tune is an entirely different ballgame, let alone modifying it.

 

[toyotanos]

I figured 3p would find this one- he's the guy who really knows computer tech. We're still pretty far behind the curve, I mean, I can't even recalibrate the speedometer for wheel changes, nor can I change really anything inside the tune unless it has a reflash. Makes customer complaints interesting to deal with when they're coming from different makes.

Oh, and I'm just a dealer tech, nothing special or awesome. lol

 

[hvyman]

Ya toyotas tech adjustment is very little.

Im a tech at benz atm and flashes are done daily to allsorts of different things. some take 2min and other 140min to flash. Some cars have like 50 control units and all of them can be flashed. Can check the wiring of all circuits for what that control unit controls if there is an issue and detrime if its a motor issue or a wiring issue. Can chek operation of things with the control unit and sds. Can even check engine compression. Its pretty impressive but its a lot of shit to learn and remember.

 

[Pyro15D]

Steve, (I'm assuming your name is Steve) it's all good. I work on electronics for the Navy so I am pretty far removed from the automotive world! It is really unfortunate that Toyota doesn't allow people to compensate for different tire sizes though, especially on a truck! Does that mean that in order to recalibrate the speedo, you have to splice in a speedo converter? That idea really bugs me. I feel like it is a band-aid fix because being a digital signal, we should be able to modify it.

hvyman: On the subject, one of my friends is a truck driver and the newer Volvo truck he is driving has some sort of SATCOM datalink. If there is a problem while he is driving, he can call Volvo up and they will analyze the engine and troubleshoot WHILE HE IS DRIVING! They can even fix issues via computer. That sort of technology amazes me. It isn't particularly tough I guess but I still find it fascinating. On the other hand, he says they know exactly how you have been driving and if you've been abusing the truck, they can knick you for it.

 

[toyotanos]

Yup, I'm Steve for sure. Only make I know has the adjustment is GM since a couple of the guys I work with used to do GM. I dunno, so many things could be easier if I could touch settings, but then again I know guys in this shop I wouldn't let change my lawnmower oil so yeah...catch-22 I guess.

 

[Pyro15D]

Well, I'm Dane. Nice to meet you Steve. I wish Toyota would at least unlock a couple things for us. I have the Mini VCI cable and the Techstream software but it doesn't really let me do a whole lot. Hopefully they will come out with a version that runs on a 64-bit PC but probably not...

As far as some Toyota techs, I know how you feel. I came in and paid $100 for the "diagnostic service" for them to see what the heck is wrong with the A750 transmission in my truck. On 1/4 throttle between 35-45 MPH the truck will shake like I'm driving over the rumble strips on the side of the road. If I let off or give it more gas, it goes away. If I drive with the overdrive disengaged via the switch on the stalk, it doesn't occur. It seems like it happens when the transmission shifts into 5th gear and the torque converter locks up. It has something called a flex-lock converter. I know it is supposed to make the shifts smoother but honestly this is a truck. I wish I could just program it to delay the shift till it reaches 50mph. It was an issue with the 07+ trucks but I seem to be the only friggin guy to have that issue with the Gen1 truck. FML. Where was I going with that? Oh yes. Anyway, the tech drove it around for over an hour and "couldn't replicate the problem" so he had me drive around and show him. His response? "Not a big deal." "It is just a comfort thing." "It isn't hard on the drivetrain." I dunno. To make the truck shake that bad I imagine severe wear and tear on the rubber mounts at least! Might as well have burned the Benjamin.