Toyota ECU Questions!!

[Moose]

Hi guys,

I have an 00 GS300 that i have done a single turbo GTE and Getrag swap with.
I have some questions regarding the ECU and electronics in general...

I will be using a Haltech Platinum Sports 2000 stand alone for engine management which will include:
injectors
ignition
fuel pump control
water temp sensing
cam/crank angle sensing
TPS
VVTi
idle control
thermo and oil cooler fans

I need to have the factory ecu in place for the following things to work:
tacho
temp gauge - not vital as i have an aftermarket anyway
oil pressure light
oil level light
charge light
aircon control

From what i understand, to be able to piggy back it I will need to common the Crank & Cam angle sensors, the water temp sensor and the TPS (which is actually a Nissan item).
It will also still utilise the security system that is embedded in the NA ECU

My Concerns/Questions:
I am concerned about interference on the Cam & Crank angle sensors by having both ECU’s commoned.
I am also worried that the factory ECU may simply go into limp mode and provide none of the functions i want from it, due to having a substantially limited amount of inputs compared to the factory setup.

Can anyone provide ANY sort of information regarding this type of setup or forward me onto someone that may know?

Many thanks in advance!

[George]

Double ECU setup is also common among Altezza swappers.
Overall, Toyota ECU's are very straightforward, there's no magic about them. Even without crank signal, native ECU would still output everything you need except tacho signal of course.
I would not recommend running 2 ecu's to single cam sensor in parallel. Consider installing a second sensor somewhere. If I had to install two ECU's in my own car I would probably make an electronic circuit that would buffer sensor's signal and forward it to the auxiliary ECU that controls the gauges. The concept of buffering is very simple and any knowledged guy would make one for you (it consists of some 6-10 small cheap parts depending on design, what it does is merely decoupling signal source and its load from possible interference).

The only double ECU setup issue I know so far is that on some models (JZX110 for example) fuel level indicator may work weird (I relate it to the fact native ECU not calculating fuel consumption anymore)

[dumbass]

ive done shotlaods of microtechs on 1js and some were piggyback so the auto still runs
piggybacking crank and cam sensors is fine unless u start having problems and trying to diagnose
then u will find it hard to blame something but I know on 1js its fine to piggyback them

to do it properly u need to add an extra coolant temp sensor as u cant piggyback the orig
coolant temp sensor and get correct results

tps u just wire it to orig ecu and just piggyback the signal wire

in the end u can do two exact setups and have different issues
so u just suck it and see then fix the problems once u get engine to run

all the dash should be fine as no wiring for dash needs to goto haltech

[wilbo666]

to do it properly u need to add an extra coolant temp sensor as u cant piggyback the orig
coolant temp sensor and get correct results

You could look at removing the pull up resistor from inside the aftermarket engine ECU (or perhaps there is an option to disable it?) and then you "should" be able to back this sensor also...

If the aftermarket engine ECU has the same value pull up resistor as the OEM ECU then you could also disconnect the pull up resistor out of the OEM ECU instead as another option...

Cheers
Wilbo

[dumbass]

ok cool
ill let the customer attempt that next time hehe

haltech only have pull up resistors on coolant wire and air temp wire
all others don't have a pull up but if u fit a two wire oil temp or trans temp sender u need to fit a pull up resistor

I might need to test it next time running two temps on a haltec and do not use
the proper coolant temp wire

so I just stay clear of fking with ecu internals incase I fk them then I need to explain what I just did

[wilbo666]

Just trying to offer information / solutions, and as I said I'm sure there are aftermarket engine ecus that allow you to disable the internal pullups.

I see you edited your response to 'soften' it slightly



Cheers
Wilbo

[dumbass]

yes I remembered a haltech I did 3 weeks ago and had to set up multiple temp senders

[Moose]

Thanks for the info so far guys, toymods always has some very knowledgeable people getting around

Wilbo, i have used your website for a few things during this build, mass props to you!! (possibly need to get the speed trigger wheel design you did also). Can you shed any more light onto/confirm any of the above info?

[wilbo666]

Wilbo, i have used your website for a few things during this build, mass props to you!! (possibly need to get the speed trigger wheel design you did also). Can you shed any more light onto/confirm any of the above info?

Thanks

For the rest it sounds like you have most of it covered...to be honest I haven't ever really spent much time thinking about the requirements to piggy back and leave an OEM ecu in place as you need to.

But some quick thoughts in regards to piggy backing,

TPS = No issues
Crank & cam = try it and see if you have any issues would be my suggestion
Coolant temp = have a bit of a look at what the after market ECU can do or fit an additional sensor (Not really that much effort to fit an additional sensor really...)
Speed = Diff mounted trigger wheel is an option or look at feeding the V160 speed sensor to the OEM engine ECU (drgs for diff trigger wheel are on my wiki...)

George also raises a good point that the fuel gauge / trip monitor will likely get broken.

I assume you are going to fit a non VVTi intake and throttle body as at a quick look the Haltec doesn't support the FBW?? You will loose your cruise control as a result of this FYI, but you do gain an ISCV and air intake temp sensor...

Also not sure if you are aware but it took me a while to find out that the missing teeth on the crank trigger are outside the first firing period... this may effect how you wire up the Haltech....
See http://www.adaptronic.com.au/forum/i...p?topic=2634.0

I'm sure you will come across a whole lot of little things to sort out

Cheers
Wilbo

[Moose]

thanks for the reply!
Firstly, George... Do you have any links to information regarding this 'buffering' scenario? I have done a bit of a google search with limited success...

Wilbo,
regarding the speedo, a mechanic at lexus told me that the 160s have a hub mounted speed sensor? Im not convinced that they do (maybe something to do with the abs system?) but wondering if you knew anything of it.
Also cheers for the crank trigger info, ill have a look at it.

I have fitted an aftermarket inlet manifold and throttle body to get rid of the FBW (i have since discovered throttle conversion kits oh yahoo auctions -_-). In an endeavour to retain the cruise control i have fitted a cruise actuator from a VZJ90 prado. In regards to wiring, to my knowledge the cruise system is independant of any other system, so i am hoping that i will be able to fit a cruise ecu from a prado and use the factory stalk on the coloumn for control.
Anyone that can comment on that aspect, im all ears!

Also ideas on getting the fuel gauge working properly? wiring something directly to the dash?

I have purchased a wiring diagram book for a 2000 gs300 so hopefully that will help with nutting things out

[wilbo666]

Wilbo,
regarding the speedo, a mechanic at lexus told me that the 160s have a hub mounted speed sensor? Im not convinced that they do (maybe something to do with the abs system?) but wondering if you knew anything of it.
Also cheers for the crank trigger info, ill have a look at it.

Yes, I would expect JZS16x to have hub mounted ABS sensors. I guess it is possible that the ABS ECU sends the speed signal to the dash and as such your removal of the auto transmission speed sensor won't stop the dash speed signal...

To be honest I don't know, but if I had to take a guess I would suggest that the auto transmission speed sensor and the engine ECU were responsible for sending the speed signal to the dash...

Let us know when you find out

I have fitted an aftermarket inlet manifold and throttle body to get rid of the FBW (i have since discovered throttle conversion kits oh yahoo auctions -_-). In an endeavour to retain the cruise control i have fitted a cruise actuator from a VZJ90 prado. In regards to wiring, to my knowledge the cruise system is independant of any other system, so i am hoping that i will be able to fit a cruise ecu from a prado and use the factory stalk on the column for control.
Anyone that can comment on that aspect, im all ears!

I don't know the specifics of the VZJ90 Prado cruise control system, but most of the earlier (Non FBW engines) cruise control systems are independent as you say.

You'll need the actuator and the cruise control ECU and will need to wire it up with the speed, brake, clutch, ignition, cruise switch, etc signals. I would expect your existing cruise control stalk to work OK with an older cruise control ECU.

Personally if it was me I'd use the cruise control ECU / system from something like a JZZ30 Soarer, as the weight of the car, engine performance etc (which I would expect to affect the response characteristics programmed within the cruise control ECU) would be much closer matched to your car than a Prado...

Cheers
Wilbo

[George]

Moose, try googling this "An op-amp–based unity gain buffer amplifier"

[Moose]

thanks for the info guys,

for anyone that is interested i got t running!

at the moment it is running the crank and coolant sensors doubled up. the only noticeable thing i can see is that my coolant temp reading on my haltech is about 6 degrees different to my defi water temp gauge (they are side by side).

Aside from that, everything seems to be working as normal so far besides the speedo, air con control (no gas to test) and the fuel gauge (only put about 20L in to start it. it is showing a fuel level similar to that amount, but cant say for sure until i fill it up).
Although i havent driven it yet, i have had it up to operating temp a few times now and all seems ok.

As far as the speedo goes, after looking through the wiring manual i bought, i have discovered that the 1UZ models did infact get its speed signal from the ABS system, while the 2JZ models used the signal from the transmission.

Im wondering if having a working speedo is as easy supplying the speed input on the ecu with a signal from the ABS unit.
I havent looked into much else at the moment as i'm more or less waiting to see if any problems arise during the tune (as far as the commoning of sensors etc).

[JP]

on some IS200/300 swaps, one way to get the speedo working is to wire it from the ABS unit, eg: http://my.is/forums/f114/how-abs-spe...-5spds-412759/

[Moose]

So i decided to bump this thread up instead of starting a new one for my next question, but briefly following on from the above...

The fuel gauge seems to work correctly from F until the 1/2 tank mark, but doesn't go below that. (not overly worried about it really)
The speedo works fine without any modification so i can only assume it is getting a signal from an abs sensor (cant complain there)
I ended up getting the central locking/boot release to work as normal, although the immobiliser is still not functional as far as i can tell.
I have not attempted any of the cruise control as yet due to ironing out some things as far as drive-ability goes.

SO. The next chapter.
I've started getting ignition breakdown on .8 bar plus recently. i gapped the plugs down a bit more and got around 1 bar out of it, but still well short of the 1.2 it normally runs.
I've purchased some d585 LS2 coilpacks as an upgrade. These coilpacks have internal ignitors in them which means i can rewire them directly from the haltech and delete the factory ignitor - all good.

My issue is with my tacho. It gets its signal from an output on the ignitor
Do these work by way of converting the IGF signal into something that the cluster can interpret? (5v squarewave?)
The other thing that sprung to mind, will the fact that i will now have 6 IGT signals instead of 3 make a difference to anything besides the fact i will need to update my tune to reflect a direct fire setup as opposed to wasted spark?

I should point out that currently the Haltech controls ignition.
I thought that the factory ecu would be required in some way for the tacho to work, but after looking at the wiring diagram it appears that the cluster is fed directly from the ignitor.