EVO8 Bench harness works.. Mostly..
You know, technically I wonder if you could mod a rom well enough to operate standalone without inputs, without any errors and shows appropriate "output" in OBD-II so you can use it as a surrogate for the original ECU so it will pass an inspection with nothing connected to it but switched power, RPM and VSS signals, and the OBD-II port.. This would allow you to run a standalone.. Hmmmm...
You know, technically I wonder if you could mod a rom well enough to operate standalone without inputs, without any errors and shows appropriate "output" in OBD-II so you can use it as a surrogate for the original ECU so it will pass an inspection with nothing connected to it but switched power, RPM and VSS signals, and the OBD-II port.. This would allow you to run a standalone.. Hmmmm...
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Last edited by donour; Mar 23, 2007 at 03:44 AM.
I made a dumb error in wiring last night because I was tired, I put the indicator lamps in-line to each of the power sources required by the ECU, I wanted to be able to know if any one particular line had no power, became disconnected, or had a problem, only I forgot one thing... The Indicator lamps I was using are LED's with current limiting resistors.. So of course it wasn't allowing enough to pass through to the power ECU.. OOPS! I'll have to fix that this morning.
I have to admit putting this together was tedious and I should have left it as a hacked together setup, but I'm a stickler for details and wanted something more durable and presentable. Next time around it would obviously be much quicker to assemble.
But once I fix this thing up this afternoon, I now have the ability to test rom mods, log data, and all sorts of things that I used to have to run outside and test in my car. (with the exception of proper live data that is) This should allow my development to go alot faster than it had been.
I'm hoping in the future I can add signal generators and simulated loads for different sensors and relays so I can actually get the ECU to register real data, this will allow me to test alternative sensors and build scalings for them. Turns out those indicator lamps might make good "Fake load" for different things.
I have to admit putting this together was tedious and I should have left it as a hacked together setup, but I'm a stickler for details and wanted something more durable and presentable. Next time around it would obviously be much quicker to assemble.
But once I fix this thing up this afternoon, I now have the ability to test rom mods, log data, and all sorts of things that I used to have to run outside and test in my car. (with the exception of proper live data that is) This should allow my development to go alot faster than it had been.
I'm hoping in the future I can add signal generators and simulated loads for different sensors and relays so I can actually get the ECU to register real data, this will allow me to test alternative sensors and build scalings for them. Turns out those indicator lamps might make good "Fake load" for different things.
Last edited by MalibuJack; Mar 23, 2007 at 06:10 AM.
I might have damaged my spare ECU, I flashed an 03 rom onto an 05 ECU, there shouldn't have been a difference in the ECU's, but be careful, there might be.
I'm not yet sure if its the bench harness or the ECU itself, so when I have some time I"ll plug it into my car and try to read it there.
I'm not yet sure if its the bench harness or the ECU itself, so when I have some time I"ll plug it into my car and try to read it there.
LOL, I had a Nasa engineer once say to me "Even rocket science isn't rocket science"
What he meant was that to get a job done, you have to work smart, not work hard. And of course the KISS method, Keep it Simple Stupid..
What he meant was that to get a job done, you have to work smart, not work hard. And of course the KISS method, Keep it Simple Stupid..
The ECU wants analog signals of some form or another.. if I built a tool that took the values from a log and created analog output for the ECU, it probably would work. Unfortunately the sample rate is somewhat slow for logging when you want that sort of resolution.
One of the Aktivematrix members suggested a microcontroller to generate the signals that have some synchronization required and are square-wave (hall effect sensors like the Crank angle, cam angle, etc..) Injector and ignition drivers can drive LEDs with the proper resistance across them, also be good indicators of what each is doing. SOlenoids and relays can be handled the same way. The O2 sensors can use O2 simulators, and their heater circuits can be done with resistors.. so I think I can do this fairly easily.
This may sound insane, but there's a method to my madness. If I can simulate all the signals properly, it makes it easier to test new alternative sensors, and/or how modifications affect these periphery devices.
The whole point is to make the time I spend testing this stuff as productive and easy as possible. I dont know about you, but running out to the car to change something, test it, then do it over and over again (either for ECU mods, or testing my logging software) took lots of time and got old really fast when the weather was crappy. Its the epitome of Working Smart, not working hard. The time it took to develop the bench harness will/has paid back tenfold in my productivity.
One of the Aktivematrix members suggested a microcontroller to generate the signals that have some synchronization required and are square-wave (hall effect sensors like the Crank angle, cam angle, etc..) Injector and ignition drivers can drive LEDs with the proper resistance across them, also be good indicators of what each is doing. SOlenoids and relays can be handled the same way. The O2 sensors can use O2 simulators, and their heater circuits can be done with resistors.. so I think I can do this fairly easily.
This may sound insane, but there's a method to my madness. If I can simulate all the signals properly, it makes it easier to test new alternative sensors, and/or how modifications affect these periphery devices.
The whole point is to make the time I spend testing this stuff as productive and easy as possible. I dont know about you, but running out to the car to change something, test it, then do it over and over again (either for ECU mods, or testing my logging software) took lots of time and got old really fast when the weather was crappy. Its the epitome of Working Smart, not working hard. The time it took to develop the bench harness will/has paid back tenfold in my productivity.
Last edited by MalibuJack; Mar 24, 2007 at 06:43 AM.
Jack,
I know this sounds weird but if you pick up an old analog music synthesizer module at a flea market or something you could generate a square wave easily. You could then easily adjust frequency, amplitude, etc.
This just pops in my head because I'm staring at a module in my room right now that would do this. Voltage may be a problem though. But you could use MIDI to control timing. I know, I'm weird.
I know this sounds weird but if you pick up an old analog music synthesizer module at a flea market or something you could generate a square wave easily. You could then easily adjust frequency, amplitude, etc.
This just pops in my head because I'm staring at a module in my room right now that would do this. Voltage may be a problem though. But you could use MIDI to control timing. I know, I'm weird.
I thought about that too.. 
But fortunately its not a very high priority where I'll lose sleep. In reality the crank sensor and cam sensor need to be synchronized as that is how the ECU knows the proper ignition trigger timing (Ever see how poorly an engine can run with a cam sensor 180 degrees out of phase?)
But fortunately its not a very high priority where I'll lose sleep. In reality the crank sensor and cam sensor need to be synchronized as that is how the ECU knows the proper ignition trigger timing (Ever see how poorly an engine can run with a cam sensor 180 degrees out of phase?)