legacycentral bbs

So I'm trying to locate my ecu so I can get my car tuned
Can you guys guide me to where it is?

Left knee +12 inches forward in a USDM sport sedan

So if I'm sitting in the drivers seat. Twelve inches from my knee would be the ecu?

Yes.

under the dash, to the left of the steering wheel.

How exactly does the tuner plan on working on an ECU which isn't reprogrammable?

It is reprogrammable. Just noone has taken the time to document the programming of the ECU yet.

Really? I thought that's the primary reason why RevTronix/etc went with the plugin ROM (besides the obvious safely of not toasting the ECU on a bad flash). heh, well anyways I'd highly doubt anyone is going to spend the time figuring it out.

If your talking about a USDM Legacy SS/TW ECU, then it is not reprogrammable. It IS chippable.

To my knowledge, only Revtronix has ever brought a product to market. Rob was working on it, but the fact that an EJ20G ECU can be used with relative ease instead put that idea out to pasture for the time being.

IIRC, Revtronix product was just an EPROM simulator with accompaning software.

FWIW, his Sig states it's an EJ20G ECU, if that's accurate (and maybe they added it AFTER above comments?) there are more options for the EJ20G - besides the Rob Tune.

Revtronix chip (upper left) in the usually unoccupied EPROM port:


Mike was working on a tunable version of the chip, but left the scene before that was available.

TD

BSOD2600 wrote:Really? I thought that's the primary reason why RevTronix/etc went with the plugin ROM (besides the obvious safely of not toasting the ECU on a bad flash). heh, well anyways I'd highly doubt anyone is going to spend the time figuring it out.

I meant reprogrammable by adding an industry standard chip to the socket. The stock chip is not re-flashable.

PhyrraM wrote:If your talking about a USDM Legacy SS/TW ECU, then it is not reprogrammable. It IS chippable.

To my knowledge, only Revtronix has ever brought a product to market. Rob was working on it, but the fact that an EJ20G ECU can be used with relative ease instead put that idea out to pasture for the time being.

IIRC, Revtronix product was just an EPROM simulator with accompaning software.

RevTronix is the only mass-produced chip brought to market, yes. Many years ago NICO on this board had his ECU tuned by a shop with a custom one off chip, but that knowledge has also been lost to time.

I've worked a little bit on reverse-engineering Subaru's programming and Mike's changes but I don't have enough experience in the 8-bit Hitachi assembly language to get very far. I do have the processor spec sheet and the disassembled code on my computer right now. It's a little complex. This whole process is a little complicated by the fact that Mike engineered some changes into the Select Monitor code on his chip that prevents the ECU from replaying it's own memory over the Select Monitor interface when running with his chip. So I can dump the factory code but haven't yet bought an adapter to directly read Mike's chip which would allow me to disassemble and compare the factory code and his code for differences.

I do however have the ability and understanding to build a chip adapter and have up to 8 switchable maps on one chip or connect a chip emulator like a Moates Ostrich and tune in realtime. I just don't know yet what to change or where.

It is much easier just to go with a standalone or a RobTune at this point in time. There is no telling though if something will happen to Rob just like something happened to Mike. A one man operation that doesn't share knowledge with the community really is at risk. If I ever get any further on the ECU stuff I've been looking into, everything will be made available to this community. I'm not in it for profit.