3P's TCCS Disassembly/Analysis

[Victor Charlie]

My point was that scaling pre-ECU with a frequency translating analog device will ensure that the range of values into the ecu take full advantage of the potential 16 bit resolution without overflowing the calculated value. If the afm has a higher output range than the ecu uses we could capture that and calibrate Vf accordingly for each car. This would allow us to let more unmetered air past the afm for more flow, but correct for that based on afm signal. Problem solved, no larger afm or maf sensor needed

Sent from my DROID BIONIC using Tapatalk

 

[nikwal]

Have you guys seen this?
http://www.google.com/patents?id=kJ...=PA1#v=onepage&q=toyota karman vortex&f=false
Some useful info on how a free running timer is used and stuff.. Interresting how the resulting value always comes out correct , well really not strange but quite clever use of binary math..

I used some of that stuff for an update of my atmega8 16bit three channel pulse with lengthener/shortener.. also changing the afm frequency is not very hard using the info in that patent and a fast oc2 int..
-------------------

I have a saudi-spec 7m-ge ecu in my mk3, it's missing some hardware on o2 input.. so that's built into the avr as well using some ford patent that steps up/down fast until o2 switches then takes a short break. ANYHOW I was curious wether my ecu use the same program , if it might be possible to complete the "missing" few pieces in the ecu and enable o2 somehow hmm ..


mvh/ Niklas Wallin
nw@bredband.net

 

[Silent Deatz]

Any updates available?

 

[3p141592654]

As you may know, I am working this project with a partner who is focused on the MR2 side of things. The later MR2 ECUs use 2 processor ECUS (like the JZA80) so we have been working on getting the software in place to support both the 2 processor daughterboards and the single processor boards. This has been more work than expected, so things have been progressing a bit slowly. More to come shortly.

 

[Bmettie]

I have a couple of questions but first I wanted to say that my hot start problem has been diagnosed. I'm 99.99% sure that the fuel is boiling in the rail and I get a severe lean stumbly start, as i said in your thread a few months ago (A BHG and a full rebuild later and I'm back at it). I only get it if I catch the TCCS just prior to being hot enough for FPU hot start scenario. If its a bit longer it gets into FPU mode and will start just fine. If I run the fuel pump for a bit and get fresh cool fuel to the rail, starts just fine, when not in FPU Mode. Can you tell me what it takes to put the TCCS in FPU mode? And according to Toyota Technical articles "EFI #3" Page 9, it states that some Toyota TCCS's will use FPU during high loads and high speeds, does the 7M TCCS use those features?
ON another note I have a California 7M MT TCCS and I removed all the EGR components on the head, except the VSV and a resistor cheating the EGR temp circuit to keep the codes at bay. I've read in your thread that adding a 100 Ohm resistor to R606 in the TCCS will fix this but you only confirmed this on a GE not GTE. Can I do this to my California GTE TCCS and remove the stuff under the hood? I am currently running a MAFT-Pro in SD and have the 7M IAT and HAC signals fixed to solid inputs for tuning, if that matters at all? Thanks or any help


PS When am I going to be able to buy a daughtercard?

 

[3p141592654]

This is taken from post #535 in this thread.....

The FPU system can only be activated during cranking when the engine speed is below 300 rpm. During cranking, if the intake air temp is > 75C, OR if the coolant temp is > 100C and the intake air temp > 60C then the FPU will be activated. It will only come on when all these conditions are met.

Once the engine starts (rpm > 300), then the FPU system will continue to be enabled for up to 3 minutes. However, this will be cut short if the engine load exceeds 45%, or the short-term fuel trim goes very lean for more than 2 seconds.

So no, it will not be activated during high load etc, in fact on a turbo engine that would potentially result in a dangerous lean out under boost. It can be only activated during cranking, period.

I have a CA 7MGTE ECU but have not examined the code yet. I would guess the same resistor values would work. If you're not getting a code, then that is a pretty good indicator that all is well.

Thanks for inquiring about the daughterboard status. I've been working on a software bug that has been a real struggle. Want to get this out as a product ASAP, but its needs to be bug free and reliable or no one will be happy.

The annoying thing is that with the daughterboard, I could reprogram your hot start FPU code to start with a lower set of temperatures which would probably solve your problem completely. Stay tuned.

Also, A member on SM (rtrdpengiun) recently donated a JDM 7M ECU to me, so I will be able to pull the maps and see just how different it is from a USDM ECU. A big thanks for that.

 

[Bmettie]

Thanks So just to confirm I'll add a 100 ohm resistor to the currently empty R613 on the board, like you said in post #116? Also is there any way to change an auto TCCS to a manual(SIN2 R607)? I also have a USDM GTE AT TCCS that I'd like to experiment on first, that's why I ask.

Yea ever since I found this thread about a year ago I've been hooked. I think its great that you found a solution to the stock TCCS. Let me know when the cards are available, and I'll probably be interested in the FPU upgrade you speak of.

It will be interesting to see if there are in fact different maps between JDM and USDM.

 

[3p141592654]

Wait, don't do that! I misunderstood your solution. That won't work since the GTE doesn't support configurable options like the GE does.

I was thinking you were talking about adding the resistor at the EGR temp sensor connector. Adding a resistor at R613 will not do anything as the code ignores it.

 

[Bmettie]

ohh ok so it will only work on a ge tccs. I already have the resistor in the EGT connector. No other work around on the GTE TCCS, that you know of? What about making an auto gte tccs, a manual gte tccs? I have a Cal MT gte tccs in the car now but I have a Fed at gte tccs on the shelf that I'd like to make MT if possible.

 

[3p141592654]

That's easy. We just flash the M/T code into the A/T box, since the hardware is the same for both boxes the code change is all that's needed.

The JDM and USDM use the same boards too, but I did notice the JDM box has a few components where the USDM has nothing inserted. I still suspect that it would be pretty easy to flash a USDM ECU into a JDM ECU. Will look into it later.

 

[NDR008]

Is there any other info you still need to crack this ECU?

Hardware or software - I may be able to help.

I have been following the ECU reverse engineering activity.
It seems like the general belief was Motorolla MCU but has now shifted to Toshiba 8x.

I saw somewhere mentioned Fujitsu Ten...

What is the final status? IDA's plugin is titled Toshiba 8x, but this is community written, correct?
This could mean even though we think it is a Toshiba 8x, but we could still be mistaken about it.

 

[mk3_7m]

any updates 3p

 

[3p141592654]

Not sure how I missed post #571. The strongest evidence points to the mcu being fabricated by Toshiba (somewhere in this thread is a picture of a development board using Toshiba branded mcus) , but it really is neither here nor there. The part is exclusive to Denso, and there are no commercial variants that can be found under any name. Fujitsu 10 probably makes the knock sensor mcu, and definitely makes the A/T ECU.

We could use additional input on the later twin processor ECUs such as found on the 3S, 2JZ, and so on. We understand enough about the interchip comms to interpret the code, but there are details not yet understood. The IDA plugin was written by me based on the instruction set that has been posted by the community, and a lot of independent testing to understand the details on registers and so on not covered by the existing docs, but definitely known by others who haven't shared them.

The status is we are working towards a release. This weekend some elusive bugs were finally eliminated from the board firmware. The final hurdle is the PC interface.

 

[NDR008]

I would love to help with the PC interface side of things if you want.

 

[NDR008]

Could someone re-post the files for the PCB setup?

Thanks.

 

[3p141592654]

Which PCB setup? Best bet is to join assembla.com. That is where we keep everything organized.

NDR, what development tools are you familiar with?

 

[NDR008]

PIC microcontrollers is my latest in terms of hardware.
(I played with other stuff, but all via very easy educational stuff)

In terms of software, C/C++/Pascal

DevC++, MS Studio, etc.

I will send you a private message.

 

[NDR008]

By the way, I was referring to the PCB used to read the current MCU and reference external memory.

 

[3p141592654]

I've been disassembling a 1989-90 JDM 7M-GTE M/T ECU (89661-14231) and it shares a great deal of software with the USDM version. The fault diagnosis code seems more extensive on the USDM version, but the knock sensing algorithm is better on the JDM.

As we all know, the JDM ECU does not control EGR, and so much fuss has been made about the ignition timing differences. Well, this is in fact true, there are differences. I've compared the JDM to 91-92 USDM base timing maps and plotted the differences versus rpm and load. The JDM map is one column bigger, with entries for 6400 rpm, whereas the USDM map stops at 6000 rpm.

Positive numbers means the US map has more advanced timing, and -ve number means the JDM is more advanced. You can see that for many operating points the USDM is running more advanced, presumably using EGR to control knock. However, in some regions, the JDM is more advanced.

High rpm the JDM seems to be more advanced, and we see differences under high load where EGR is not used. Some of this may be due to the better knock detection on the JDM code or maybe higher octane fuel in Japan (?). I will post up the open-loop fuel enrichment map later once I've had a chance to compare them.

 

[NDR008]

Sorry I've not reported anything. I have recently gotten married and been unable to reply to your e-mail.

Your logic seems spot on. JDM octane rating is assumed to be better than that of USDM by OEMS.
However, some EGR at low-RPM would allow for a slightly higher advance, but at higher RPM, where "High Pressure EGR" (the type used on old cars) cannot flow, so no EGR is present to mitigate knock.

Also, considering that at that time, EGR combustion mechanisms were not well understood technology, at WOT condition, EGR will reduce BMEP, so advancing the ignition would be the only way to recover the lost torque.

Regarding knock detection... very hard to say, because I do not know the method used in cars that old, but in general, it is not a reliable science. At some RPMs, sometimes knock sensors need to be ignored, because the tapping caused by valves opening and closing are similar to kock (as far as the sensor can see).

So setting the right calibration to correctly detect but not be too over- or under- sensitive is difficult especially for all RPM ranges. (Which is why ECU code has become too complex to program in ASSEMBLY or C).