JZX90X Plug-In ECU Hold Power Wiring

[fifty3bags]

I'm trying to ensure I have my ECU hold power wiring correct for the stock stepper ISCV. For the JZX90X ECU, pin 59 is the main relay output, which I will wire to one side of the Main Relay coil, pin 86. My understanding of the OEM ECU output is to output voltage for a few seconds, basically a Hold Power output, is that how the JZX90X ECU works as well?

 

I would wire in a 1N4007 diode between Ignition Switch wire (ECU pin 14) and ECU pin 59. Main Relay pin 30 will output to the ECU pins 99 and 100, as well as the ISCV. Finally, Main Relay pin 87 to +12V battery power and Main Relay pin 85 to ground or batt (-). See my attached sketch for wiring. 

 

My question is whether this connection is sufficient, or if I need to wire differently utilizing the Main Relay Control (Injector 8) for ECU Hold Power.

[Adamw]

If you have a plug-in ecu the hardware is already built-in and the hold power is already set up and working in the base map, you dont need to do anything.

[Tom H]

Hi Adam, 

I have a JZX90 plug in, I purchased when first released and am now integrating it into the car. It has been updated to the latest software version. I have the hold / power relay wired as above (The 1J is actually in an RX7 but uses factory Toyota engine loom etc). Note -  "Ign switch" should actually be pin 85 (C86 pin 9) not pin 14 as above. 

The ECU powers up as expected and I can get online with PC Link. When the key is turned off the Physical output (Injector 8) drops out and the ECU turns off. I can see in the software as the ECU dies the ECU Hold power trying to activate. I currently have the ECU hold configured the same as the G4x jz90 base map. 

The only power I have to the ECU is +B +B1 on pin 99/100 (C86 pin 22/23). Based on wiring information I think this is correct.

The Link G4x appears not to use Pin 93 (C86 14) +12v constant which the factory Toyota ecu would have used. 

Any idea why "inj 8 - ECU hold power" drops out as soon as the key is switched off? 

 

Thanks 

Tom 

 

 

 

 

 

[fifty3bags]

Tom, 

 

You’re right, I meant to update that on my diagram before submitting my post, but apparently I forgot. Thank you!

 

You’re correct, the ECU does not use pin 93 for constant power. I checked with Lind support on that as well. 
 

Do you have the diode installed in the circuit between pin 85 and 59?

[Tom H]

7 hours ago, fifty3bags said:

Tom, 

 

You’re right, I meant to update that on my diagram before submitting my post, but apparently, I forgot. Thank you!

 

You’re correct, the ECU does not use pin 93 for constant power. I checked with Lind support on that as well. 
 

Do you have the diode installed in the circuit between pin 85 and 59?

I did have the diode in, but I took it out last night on Adams comment about it not being needed. The car switches on and off on the key just fine without it as Adam stated. 

I can see the hold trying to latch in PClink but cant. 

[Adamw]

For ECU hold power to work the wiring will need to be as per factory.  The main points:

1. An ignition switch signal that is +12V when ignition is on, to Pin 85.
2. The main relay coil connected to pin 59, the other side of the relay coil connected to ground.
3. +12V Power supply from the main relay high current contacts to pins 99 & 100.  The supply to that relay must be constant 12V - not supplied from some other relay.
4. +12V battery feed (constant 12V) to pin 93.
5. And of course at least some of the main grounds connected.

[Tom H]

Cool. I will add 12V const to pin 93 and see how I go. 

All other points are as instructed. 

I assumed it didn't need it based on links pinout in the JZX90 manual. 

 

Thanks Guys 

[Tom H]

10 hours ago, Tom H said:

Cool. I will add 12V const to pin 93 and see how I go. 

All other points are as instructed. 

I assumed it didn't need it based on links pinout in the JZX90 manual. 

 

Thanks Guys 

Can confirm 12v Const is required.