Hi All:
This year Yamaha release the most sophisticated sportbike to date. It has cutting edge electronics on board. The ECU controls the throttle (fly-by-wire), has a servo controlled exhaust butterfly ("EXUP"), and variable length velocity stacks. Unfortunately, it also has a bug/problem where under very specific conditions the fly-by-wire seems to ignore the riders input and stays constant in what feel like a pronounced lag. From the discussion on the R1 forum, Yamaha has no plans to correct it.
So I guess its up to us, the geeks of the proletariat! Besides, it would be great to be able to fine tune the bike when the exhaust is replaced or the intake is modified. Let me start the thread off with the information I've accumulated up to this point:
Nobody makes a system for tuning the maps of a stock ECU. There are data loggers. Therefore, there must be a fairly standard communications protocol which, I assume, is OBDII. Also, Yamaha makes a race version of the ECU. However, it requires a different wiring harness to work and looses most of the street amenities in the process. The race ECU accepts remapping and Yamaha provides the cable/adapter as well as the software.
I've reviewed the wiring diagrams for both the stock and race systems. What I've noticed is there are a couple of comm lines marked DRX and DTX that are in the race ECU that are not in the stock version. Further, I've noticed that the pins exist in the stock ECU but are not populated in the stock wiring harness. Both the race and stock ECUs have a pair of serial lines that communicate to the stock instrument panel. The stock panel works on both systems and is used for reviewing DTC's as well as reviewing sensor readings in realtime. Also, the stock instrument panel seems to be able to shift the entire fuel map by small increments one cylinder at a time in the stock ECU. The service manual refers to "CO Adjustment Mode" for this but doesn't describe how to get into it. (I can probably contact the guys at the last dealership that I worked for. They will give me the scoop, I'm sure.)
Yamaha literature describe the ECU as composed of:
A) ETV main CPU (32-bit) which is connected to the throttle body in the schematic.
B) ETV sub CPU (16 bit) also connects to the throttle bodys.
C) FI CPU (32 bit)
D) Throttle servo driver and sensor
E) A bank of sensors including engine revs, neutral switch, crankshaft position, coolant temperature, and atmospheric pressure sensors. (I also know it has an O2, ambient temperature, EXUP position sensors as well as an EXPU servo driver but they aren't shown in the schematic)
F) Finally the driver for the variable length intake is on board.
Does that sound familiar to the Drive-by-wire systems?
I read in some review that its a Mitsubishi ECU but its is clearly labeled as a Denso unit. Here are a few pictures. It is obviously well potted and not easily disassembled. I'll follow up this posting with more images.
One last thing. I have downloaded the firmware for the latest setting for the race ECU. Can that provide any clues?
(BTW: You won't see the images unless you are registered, sorry.)