Link G4x xtremex wire in advice

[madmonkey]

Hi,

I’m hoping if someone can help me by looking over the following PDF files I created to check if I have everything in order before I start wiring the ecu into my car.

Vehicle is a 1994 Toyota MR2 turbo

ECU is a G4x xtreme x wire in

I decided on the wire-in version instead of the plug in as there’s more I/O available as the plug in version doesn’t have a few pins exposed. Additionally there’s a possibility I might do an engine swap later on down the track hence going with the wire in. 

The plan is to make a patch harness which connects to the stock wiring loom, however I noticed there’s a few incorrectly labeled pins from diagrams I found online compared to the labels printed on my stock ECU.

I’ve copied the G4X MR2 LINK V3 plug in pin out (so I can play around with the base map) found in the online manual and have matched up most of the corresponding pins to A and B looms. I just need clarification regarding the grounds, which ones to use for which pin off the OEM loom.

I take it anything sensor based uses the Shield/Gnd or the Gnd Out? 

The pin positions highlighted in red (middle pin out diagram) do not have connections from the stock ECU loom plugs. (Top diagram is from a website I found online some with different labels, middle one is what matches mine.

MR2 ECU WIRING - LINK G4X XTREMEX-compact B PLUG.pdfMR2 ECU WIRING - LINK G4X XTREMEX-compact C PLUG.pdfMR2 ECU WIRING - LINK G4X XTREMEX-compact A PLUG.pdfMR2 ECU WIRING - LINK G4X XTREMEX-compact LINK LOOM A&B SPARE.pdf

Sorry for the long post and thanks in advance.

[koracing]

I'm assuming this is the 3rd generation motor?  I.e. is this a USDM 94 turbo or outside of the US 94 turbo?  The function and wiring is slightly different between the two, but most things should be the same or similar.  I'll look over your files and let you know what I think.

[madmonkey]

Hi Kris,

Thanks.
I’ve actually finished the test patch harness, just need to pot it and test it out. The files have been changed, below are the latest ones.

Also it’s a JDM rev 3 car with a gen3 3sgte.

MR2 ECU WIRING - LINK G4X XTREMEX-compact-EM A PLUG.pdf MR2 ECU WIRING - LINK G4X XTREMEX-compact-EM B PLUG.pdf MR2 ECU WIRING - LINK G4X XTREMEX-compact-EM C PLUG.pdf

[koracing]

If you haven't finished it I would add a couple things:

1. DI input for the TE/TE1 pin and set this to the lock timing function (for checking sync similar to the way the OEM system worked)

2. DI input for the ELS pin - this can be assigned to a GP idle up to make electrical load (Headlamps or rear window defrost) affect the idle via this input

3. DI input for the PS pin for power steering request input funcitonality

4. an aux output to the PSCT pin this would be to cancel the steering if memory serves and I'm not 100% sure on the exact logic to make it work - if it needs to see a high or a low output from the ecu to work (toyota usually likes to use grounds)

Are you certain those are the correct pins for PS and PSCT (54 for PSCT and 66 for PSCT)?  I have Gen2 late pinout as PS on 54 and PSCT on 56 - and I realize the gen3 may be different but I've never been able to 100% confirm as we never had OEM rev3+ cars here in the states. 

Given the choice also I would put ECT on Temp4 and leave AN Temp1 for auxiliary input as it can have the internal pullup turned off (Temp2 can also do this) and read in many other types of sensors, where Temp3 and 4 can not. 

I highly recommend and personally always install a fuel pressure sensor on projects I'm doing.  This aids in to use in the fuel model as well as aid in discovering fuel delivery issues or faulty regulation of the fuel. 

You can use the Temp2 input for an auxiliary input as well since you don't need the airbox temp sensor.

[madmonkey]

4 hours ago, koracing said:

Awesome thanks or the reply! I was just about to start potting the jumper harness when I saw a notification pop up! I'll follow what you suggested in your reply for 1,2,3 & 4. I forgot to mention I bought a CAN lambda sensor and will be purchasing a flex fuel sensor as well as a few temp/pressure sensors for oil, fuel and water.

1. DI input for the TE/TE1 pin and set this to the lock timing function (for checking sync similar to the way the OEM system worked)

2. DI input for the ELS pin - this can be assigned to a GP idle up to make electrical load (Headlamps or rear window defrost) affect the idle via this input

3. DI input for the PS pin for power steering request input functionality - I was wondering why the plug-in version didn't have this pin connected.

4. an aux output to the PSCT pin this would be to cancel the steering if memory serves and I'm not 100% sure on the exact logic to make it work - if it needs to see a high or a low output from the ecu to work (toyota usually likes to use grounds)

Are you certain those are the correct pins for PS and PSCT (54 for PSCT and 66 for PSCT)?  I have Gen2 late pinout as PS on 54 and PSCT on 56 - and I realize the gen3 may be different, but I've never been able to 100% confirm as we never had OEM rev3+ cars here in the states. - I actually opened up my stock ECU to see what the labels for each pin was. (as its printed on the PCB) I then cross checked it with the pin out from this site; 3SGTE Engine ECU Layout – Shoarmateam as well as Links description for the MR2 Link V2-3. I'll attach a picture of the labels off my stock ecu for your reference.

Given the choice also I would put ECT on Temp4 and leave AN Temp1 for auxiliary input as it can have the internal pullup turned off (Temp2 can also do this) and read in many other types of sensors, where Temp3 and 4 can not. - Thanks, I'll modify this as well. 

I highly recommend and personally always install a fuel pressure sensor on projects I'm doing.  This aids in to use in the fuel model as well as aid in discovering fuel delivery issues or faulty regulation of the fuel. - regarding sensors I was thinking about getting this one for fuel pressure; Syltech - 10 Bar Motorsport Precision Pressure Sensor DTM06-3S-E007 Co — Goleby's Parts (golebysparts.au) and these for oil and water Syltech - 1/8″ NPT Pressure & Temp Combo Sensor DTM04-4P Connector — Goleby's Parts (golebysparts.au) as they have the DTM plug, what are your thoughts? 

You can use the Temp2 input for an auxiliary input as well since you don't need the airbox temp sensor. - Is there any benefit in keeping the sensor for the airbox?

 

 

[koracing]

None of those pins look like they are designated PS or PSCT - but a lot of the pins are designated as LEV, MTT, M+, and M- which are related to the ST205 A2W intercooler/water pump - what is the part number of the ecu on the outside of the case?  89661-?????

As far as the pressure/temp sensor for oil and fuel: if you run a flex fuel sensor it should be able to provde fuel temperature so a fuel pressure sensor would be all that would be required, but no problem having some redundancy.  The Oil pressure position of choice is typically the port off of the cylinder head where the factory idiot light switch is, but if you mount the sensor there you won't get very accurate temperature readings.  The best place I've found for oil temp is the pan, which obvioulsy would be an issue with a combination sensor.  If you install the combo sensor in a pressure take-off spacer between the filter and the pan that could work also but the temp sensor ideally needs to be somewhat in the flow of oil to get a good temperature reading.

Sorry I missed your replies in the quoted post above.

I have no information or experience with the syltech sensors, but I do like they use Deutsch DTM connectors.  I may try some in the future.  

I don't see any real benefit to having the ambient engine bay air temp, except possibly to control some engine lid fans.  The oem sensor calibration is also unknown to me but may match something in the calibration drop down closely enough.  Most any trims you might possibly use this sensor for are largely accommodated by the manifold air temp, and coolant temp trims already built in.  

[madmonkey]

 

I just checked my stock ECU and it is 89961-17460

 I guess it’ll be better to run dedicated sensors for temp and pressure from different locations for better accuracy as opposed to combined? I currently have a SARD oil filter sandwich plate with a temp sensor for my defi oil temp gauge. Perhaps it’s best to use that and send that into to the ecu.

Yes the Syltech sensors do look interesting as they are Deutsch DTM, just need to figure out if clearance is ok depending on where they’re mounted.   
 

[koracing]

I think for the oil I would run separate unless you can get the pressure/temp into the sandwich plate.  Usually I take pressure at the head after the head gasket, as it's the last stop in the oil system before it goes out the cam journals and back into the crankcase.  The DEFI temp sensor probably would work to send the signal via an analog input without any pullup as long as the gauge is also connected as it should have it's own pullup inside.  The oem o2 sensor signal or heater ground wouldn't be far away from the adapter and both run back to the stock ecu header.  With the gauge installed and running the sensor to both the gauge and ecu input you would be able to figure out and verify a calibration curve.

[madmonkey]

Hi Kris,

Sorry for the later reply.

In regards to running the oil pressure sensor I take it you run it remotely on customers cars so there’s less of a chance of the fitting/adaptor snapping off?

If so what size lines are you running to remote mount the sensor? I’ve also been looking at the Rife sensor blocks lately just unsure which way to go as I like the clean look. Here’s a link, they come in 2 3 and 4 sensor banks.

https://www.motionraceworks.com/collections/pressure-sensors