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      10-11-2016, 04:53 PM   #56
dre99gsx
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Drives: 1994 Toyota Supra
Join Date: Aug 2011
Location: NJ

iTrader: (1)

WIRING MAYHEM! Powered up the AEM, started setting up sensors and what not. Got the N52 DBW throttle body working great with the pedal. Was able to get the electronic power steering to work, but took some effort!


Still more wires to pin, but this gets messy real quick.


Started CAN sniffing and writing some code to inject CAN messages. Working on RPM signal here:


Found the correct ID and bytes for RPM - works!


Here is the speedo fooled"


Bit of explanation needed here, but RED = input frequency signal, YELLOW = simulated output crank signal 60-2 (2 pulses missing every 60)


Powering up the 2JZ with the AEM is cake, but integrating with the entire BMW electronics so that everything works as a system, is not cake. To get electric power steering, DSC, abs, and other items to work correctly, the Z4 needs to see a stock ECU which also sees a running and happy engine.

The crank signal is important here, but since the 2JZ tooth pattern is not 60-2, I can't just plug in the magnetic crank sensor to both the AEM and the stock DME. I decided to create a circuit out of a cheap PIC microprocessor I had laying around, with some simple code. The idea is to setup a Lowside driver on the AEM that outputs 1khz for every 1000rpm. Then, with the PIC, I will output the same signal, but cut out two pulses every 60 pulses, which mimics the N52 motor crank. You can see this working on the scope picture above.

I tested this on the Z4. Using a function generator set to 1khz and this circuit, connected to the stock DME, mysteriously the stock ecu thought the engine was running. Once this was done, power steering was enable, and all other ecus in the vehicle were able and ready to go.

This should allow me to continue working on OBD2 as part of this project involves full integration with no codes.
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Last edited by dre99gsx; 07-31-2017 at 02:16 PM..
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