MY05 Subaru Forester XT - G4+ Thunder

[Bram]

Hello.

So i have purchased a Thunder G4+ ECU and am attempting to wire it in.  I am actually an auto electrician by trade,  but i dont usually ever have to do installs like this.  Anyways, so far ive got a pretty good handle on most things, but ive got a few things id like clarification on.  The vehicle in question is an Australian delivered 2004 built MY05 Subaru Forester XT.  2.5L turbo engine.  DOHC.  DBW.  Intake AVCS.  Originally 5spd manual, but swapped to STi 6spd.

Q1.  Can the original subaru fuel pump duty cycle controller be used to control the tank/lift pump?  I have a DW300 pump in the main tank, which feeds to an external surge pot with a Walbro 450.  If possible, id like to use the controller to control the lift pump duty.  And use a seperate output from the ECU to switch a relay to run the main pump in the surge can.  The controller is there, the wiring all inplace, and any reduction in fuel temp/foaming is a bonus.  The fuel controller has an IG+, B-, 2 wires to the pump, and 2 wires to the ECU.  (B27 and D30 at ECU)  I presume Link has figured out the Subaru fuel pump controller for use on thier WRX/STi Plug-in ECUs.  And its proably the same unit as used on the Forester.  I did search both the forums and the PC-Link help files to no avail.

Q2.  Probably a stupid question, but just going to confirm.  For the Cam angle Sensors and trigger 2 inputs.  I noticed on the PC-Link Help file, under engine specific information, under Subaru WRX V10 EJ25.  (closest match to the forester XT)   It says to use the LH Cam sensor as the trigger 2 input.    And use the RH sensor as a Digital input.  Now my question is, is that to say use the cam sensor for cyl 2 and 4, not cyl 1 and 3?  So left hand as in your sitting in the car looking forward.  Not standing infront of the car, looking rearward.  Its just i would have thought it make more sense to use the Cam sensor that matches cylinder 1.

Q3.  For the Drive by Wire.   Im pretty confident i have wired the throttle  motor / TPS correctly.  (I found some info in these forums while searching.  And it seams to match up with the Honda diagrams as found in the PC-Link help file.  The unit also looks very similar in appearance to the Honda items.)  But i just want to confirm the wiring for the Accelerator Pedal Position Sensor.  it is a 6 wire unit.  Does anyone have any pin information on the Subaru sensor?  i have access to 2 different wiring diagrams (one OEM, the other Auto-Data) and they both show me the wiring layout from sensor to ECU.  But i dont have access to which wire does what.  Eg 5v main, 5v sub, signal main, signal sub, negative main, negative sub.  I am not at the stage of powering the ECU yet, and i have gone past the stage of being able to power the existing ECU to test things.

Q4.  Is it possible to use the Thunder ECU to control the DCCD center differential?  I currently use a DCCDpro unit.  But understand the ECU has G sensors, and access to all the same inputs the DCCDpro controller uses.  So im thinking it would be nice to streamline the system and use the ECU to replace the DCCDpro.  Allowing tuning of the center diff controll.  Has anyone done this before?  Is it worth it, or should i just stick with the DCCDpro?

 

 

Thats all i have right now.  But im sure to have more questions as i progress on the instal.  thankyou.

 

 

 

 

[Bram]

Another Question.

Q5.  Is it possible to use the Thunder ECU to control a relay after engine shutdown for a timed function?  I have built a low mount mount turbo setup on this car, and the turbo is so low that it requires a scavenge oil pump to drain the oil back to the engine sump.  if its feasable, i would like to use the ECU to keep the pump active for maybe 30 - 60 seconds after shutdown, so as to fully drain the turbo oil collector of oil.  I dont know if this is gonna be actually needed with my low mount setup, but if possible it would be nice to use the ECU as opposed to a seperate timer.

[Scott]

Hi Bram,

To answer your questions:

Q1. Yes, here is how we do it in our WRX V10 (2.5L e-throttle) plug-in ECU:

Aux Output 6 (FP Speed) goes to pin B27. Pin D30 is not used by our plug-in ECU.

Q2. Left hand is as your are sitting in the car. I'm not sure why the engineers chose that cam for the Trig 2, the pattern on both cams look to be the same, but offset. Maybe it is something to do with how the cam patterns are offset in comparison to the crank pattern.

Q3. 

• Pin C17 is An Volt 10 which is Accelerator Pedal Sensor - Main
• Pin C28 is An Volt 9 which is Accelerator Pedal Sensor - Sub
• Pin C15 and/or C16 should be +5V to the sensor
• Pin C34 and/or C35 should be sensor ground to the sensor

Q4, This may be possible, but I don't know anyone who has done it before.

Q5. Yes, this should be possible, you will need to use the ECU's Hold Power function to keep the ECU alive after the key gets shut off. See PCLink Help > Wiring Information > Power and Ground Wiring > ECU Hold Power Wiring. Scroll towards the bottom of the page and you will see two diagrams for wiring the Thunder for ECU hold power. You will want the ECU hold power timer to be set to longer than you want to run the oil scavenger pump for. You will also need to think about what condition you want to activate the scavenger pump under, maybe engine speed = 0 and ignition switch = off. You will have these conditions activate one of the ECUs timers and then have the timer activate an aux output that controls the pump.

Scott

[Bram]

Thankyou for the detailed answers.  i appreciate your time.

 

Re the DCCD.  i might leave this as existing for now and maybe look into using the ECU control at a later date once the car is up and running.  Its not a high priority for me.  The DCCDpro works fine for my application.  I set it to max at the track and min when im in the carpark.  And alsong as the hydraulic handbrake cut-out works im happy.

 

Another question.  While im running cables in and out of the cab/engine bay, i was thinking of utilising the ABS wheel speed sensors into ECU wheel speed sensor pins.  I have no idea what id use the info for at this stage.  (maybe for the above mentioned DCCD)  But i was thinking i may aswell lay the cable while im in there from ABS modulator to ECU.  Do you think CAT6 data cable would be sufficient?  it has 4 X pairs of twisted cable.  I have some of this laying around the shed.  I do also have some 2 core with shielding cable aswell.  I think the shielded cable would probably be better but, 4 x runs of it is a pretty think bundle.  Thoughts? 

 

Thanks again.

[Scott]

Hi Bram,

It would be worthwhile bringing in the 4 wheel speeds. The Thunder has 6 high speed differential wheel speed inputs, these are the ones you want to use for your ABS sensors. You will 'T' into the existing wires between the sensors and the ABS controller.

I've never done much with CAT 6 cable, is it multi stranded? If not I would try and use something flexible and multi-stranded that is shielded. The actual current requirement for the speed sensors will be very low.

Scott

[Bram]

Nah.  its a single strand of copper for each of the 8 wires.  it isnt the most flexible cable.  i think the biggest issue will be not snapping the thin strand while working with it.  i guess if im carefull with it that should be fine.  

I was more asking because of interferance and and EMF issues from each sensor causing issues with each other and adjacent wiring, as there is probably 2.5m run between ecu and abs.  I noticed the OEM use a twisted pair for original ABS wiring.  And other inductive sensors like the crank angle sensor pickup is shielded.   So dont want to run into trouble with that sort of thing.

[Bram]

Another Question on install.

How important is the Subaru OEM power steering pressure switch?  Is it worth wiring that into the ECU, or just ignore it.  The car has a Spec C quick ratio rack in it.  And it does run 295/30R18 semi slicks all round.  That plus the plated rear LSD can almost stall the car when turning in carparks etc if you dont feed it enough RPMs.  I presume the switch would be used to increase engine throttle/RPMs or something when it detects high pressure to help with smooth running under different loads? 

[Bram]

Hi Bram,

To answer your questions:

Q1. Yes, here is how we do it in our WRX V10 (2.5L e-throttle) plug-in ECU:

Aux Output 6 (FP Speed) goes to pin B27. Pin D30 is not used by our plug-in ECU.

Ok.  So I have set the fuel pump control as above (except on AUX OUT 7).  The in-tank pump primes as normal using the OEM fuel pump duty cycle controller with key on.  I am not at the stage of trying to start the car just yet though.  But atleast the in-tank prime function is working correctly.

BUT.  I cannot get the main fuel pump relay to switch on to prime aswell.  I have wired the relay 85 terminal to AUX OUT 14.  Relay terminal 86 is connected to ignition 12v+. On the ECU software,  I have assigned AUX OUT 14 as :

function = fuel pump

polaity = low

open circuit detection = off

 

Is there something i am doing wrong here?  I have tested the relay, pump and associated wiring.  Everything is good.  But no prime.

thankyou.

[Bram]

Ignore that last question about the fuel pump.  I have figured out what was going on.  I had the ECU wired like the hold power diagram, so when it gets ignition input on the ignition  sense terminal, it then turns on the main relay on, which then feeds power back to the ECU.  But i hadnt switched that feature on in the software.  So when i was powering the ECU ignition input via the key switch, it powered up the ECU, but not the main relay.  Instead it had some wierd 3 to 5v backfeed out the main power input.  I also used that ECU main relay to power the 86 terminal of the main fuel pump relay.  And I was testing things with an LED testlight.  The 5v backfeed lit the LED testlight up.  But not enough to engage the fuel pump relay.  Derp.

Edited November 26, 2016 by Bram
Spelling error

[Bram]

 

Q5. Yes, this should be possible, you will need to use the ECU's Hold Power function to keep the ECU alive after the key gets shut off. See PCLink Help > Wiring Information > Power and Ground Wiring > ECU Hold Power Wiring. Scroll towards the bottom of the page and you will see two diagrams for wiring the Thunder for ECU hold power. You will want the ECU hold power timer to be set to longer than you want to run the oil scavenger pump for. You will also need to think about what condition you want to activate the scavenger pump under, maybe engine speed = 0 and ignition switch = off. You will have these conditions activate one of the ECUs timers and then have the timer activate an aux output that controls the pump.

Scott

Going back to my question about setting up the scavenger oil pump.  I have the oil pump relay connected to AUX OUT 8.  The output works, and I can run the pump by setting the function to "On" for testing.  Now I would like the pump to run while the engine is running, then remain running for a set amount of time after engine shutdown.  Setting the pump to be on with engine on is easy.  Condition 1 is used for that - where RPM must be > 0 RPM.  I also have an engine oil pressre sensor, so alternatively could use that to trigger it aswell.  Eg Oil pressure (AN V3) must be > X kpa.

Now im not quite understanding how to set up the timer function.  I have the ECU hold power set up and it keeps the ECU powered up for the hold power time.  

But I dont really understand how the timer (timer 1 - 4) is to be configured and also which setting on the AUX OUT 8  (scavenge  pump) is to be set?  Could you please give me some suggested settings so as to how you would make the pump run for X time after engine shutdown?  

Sorry if this is a silly question.  This is all new to me still.

 

[Adamw]

I havent thought this logic through in great detail, but this screen shot should give you the basic idea.

In this example, Aux 8 will be on when condition 1 or 2 is true.  Condition 1 would be the running engine conditions - lets say RPM is >10RPM .  Condition 2 will be your shut down timer - When RPM falls below 10, Timer 1 is "activated" by virtual Aux 1 which will then start counting up (to 40sec) in the background, When Aux 8 condition 2 sees the timer count hit 30 seconds it shuts off oil pump.  Clear as mud?  Hopefully its easier than it sounds on screen...

I would try it like this and see if it behaves as expected - the part Im not sure about is the timer might start timing as soon as you turn ignition on (before you start engine), if it does you might need to add another condition to prevent that.

how to screenshot on windows

[Bram]

Thanks for the reply.  I was not aware of the 'virtual aux' features, that opens up a lot more options.  I shall have a play around and see how it goes in the coming days.  Ive still got a small amount of mechanical work on-going and havent attempted actually running the engine yet.  Im just trying to get as much ground work done before hand.  Last thing i want to do is flood the new turbo/exhaust/intake with oil.

[Scott]

I think if you keep things how Adam suggested but add a 3rd condition to Aux 8 then the  scavenge pump will not start running when you turn the key on and rpm is zero. Something like this:

Scott

[Bram]

Thanks for the replies.  I might try and do it that way, except use oil pressure as the main trigger for engine running (trigger 3).  Looking at the way Scott has suggested, it looks like the Scavenge pump trigger 1 + 2 means it will only start to run on timer once its already been running.  (from first being triggered by trigger 3 - engine RPM greater than 10.)

 

The reason i would maybe look at using oil pressure sensor input instead of RPM is i have a oil accumulator/accusump fitted.  So there would be potential for that to be discharged, and the engine not actually started (pre-oil but then no start).  And although i highly doubt the small percentage of oil that would make it through the turbo VS whats discharged to the rest of the system from the accusump would be enough to fill my turbo oil drain collector, i guess it still would be nice to drain it.  And hearing the pump run would also hopefully remind me that i have just discharged the oil accumulator.