Hello,

I am planning to setup a standalone ECU (MaxxECU) with jumper harness, so i don't need to destroy the original ECU harness.
I can try to make this write up so that it is useful with many other standalone systems as well, as there are constantly coming new standalone ECU options for this kind of setup.
As far as i know the inputs and outputs that are needed for this are following;
Outputs;
- 6 Injector outputs
- 3 Coil outputs (I think the Coil Dwell time should be 3ms. Correct this if it isn't right)
- Radiator fan switch
- Idle stepper motor this apparently needs 4 outputs.
- Fuel pump relay
- Wastegate solenoid PWM controlled

Inputs;
- TPS
- IAT
- CLT
- Cam sensor
- Crank sensor

There are few things that i am still thinking of (These determine the ecu requirements for inputs and outputs);
- Is it necessary to use PWM signal to alternator for charging control, or can that be let out completely, how would the alternator work without the PWM control?
- Can i bypass the A/C control from Engine ECU by taking the control signal directly from A/C control panel? (This would keep the A/C on in any engine condition as it wouldn't be controlled by ECU anymore)
So i am thinking to loop the signal in Engine ECU pin 57 this comes from Aircon and loop it to pin 22 AC compressor trigger.
If this is not possible this means 1 more input and 1 more output for new standalone ECU.
- Fuel pressure solenoid, i am not familiar with this but i am thinking it is used also with PWM signal, but can it be disabled somehow?

This totals at 16 outputs + possibly those open questions above AND 5 inputs, these are as minimum.

With MaxxECU you have build in MAP sensor and direct controller for bosch LSU 4.2 and 4.9 Wideband lambdas.
Any inputs regarding this kind of standalone setup is appreciated!

I am trying to use all original sensors so i can swap back the original ECU without hassle, if needed.