1G Blackbox 2G ECU in a 90 AWD

[mac 108]

I've searched and searched, but I cannot find anything specific on converting a 2G flashable black ECU to a 90 AWD.

I plan to make a jumper harness using a dead 1G ECU and the pigtails from a 2G ECU wiring harness. With the differences in the 90 cars compared to the 91-94 cars, are there any extra steps to the conversion?

Also, do I need to swap to a 2G knock sensor?

 

[steve]

The knock sensor needs to match the ECU.

The 90 ECU swaps the pins for the IPS and MAF reset when compared to the 91-94 ECUs.
The 90 ISC is connected different (which driver pins are used for which ISC coil) but I forget if that makes a difference at the ECU connector or if it's just an issue when modifying the 90 harness for a 91+ TB and ISC.

 

[mac 108]

Thanks, Steve!

I ordered a 2G knock sensor last week and I'm working on my jumper harness.

 

[mac 108]

I finally got my jumper harness finished and the car runs with the black box ecu connected. Even the tachometer works properly.

I have a Tactrix 2.0 cable and Evo Scan, but I cannot get it to get to download the rom from the ECU. It gives me an error message and tells me to check the log, but the log doesn't list anything regarding the error.

I also cannot get a handheld code reader to work. It doesn't even get power.

I figure I've got the OBD port wires connected to the ECU incorrectly.. According to the guide I used, only two wires from the OBD II port are used. Is that correct? I currently have 2G ECU pin 56 with the yellow wire and pin 62 with the pink wire connected to the OBD port.

Where do I go from here?

 

[mac 108]

Based on this post, it looks like I need to wire the rest of the connectors in the OBD port to the car's harness.

This is going to be tough to remember. I think the OBD2 connecter has 16 pins arrange in two rows.
I think mine is hooked up as follows. I know it works we used it to get my car running as I had a bad knock sensor on first start.

Pin1 is Yellow diag from ECU pin 56 on connector b-55.
Pin 4 is black ground
Pin 5 is black/white ground
Pin 7 is Pink data from ECU pin 62 on connector b-55.
Pin 16 need to have +12 volts constant

Then I just took a 1g obd1 connector and depinned everything except the first pin and use that as my flash pin. Has been working perfect for me.

Is that correct? To where do I wire the additional OBD port wires?

 

[ThunderChild]

This thread is for the evo 8 ecu but it's similar, and the OP may be able to help you out.

You won't use all the obd2 plug pins. I believe there's only 1-3 for the evo ecu. I haven't looked very hard at the diagrams yet but my bet is a flash pin, CANH and CANL

 

[mac 108]

Here is my OBD port

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[steve]

Based on this post, it looks like I need to wire the rest of the connectors in the OBD port to the car's harness.

Pin1 is Yellow diag from ECU pin 56 on connector b-55.
Pin 4 is black ground
Pin 5 is black/white ground
Pin 7 is Pink data from ECU pin 62 on connector b-55.
Pin 16 need to have +12 volts constant

Is that correct? To where do I wire the additional OBD port wires?

4 and 5 to the chassis ground #5
16 to Dedicated Fuse #11 (ECU pin 80) for unswitched +12v

 

[mac 108]

Where is chassis ground #5 located?

 

[steve]

I forgot that this was a 1G conversion. The equivalent ground on a 1G would be the ECU one by the MPI relay on the passenger side center console upright. If that's too far, any good chassis close by your connector should work.

 

[mac 108]

I found it. Thanks for all of your help, Steve. OBDII port works now.

 

[mac 108]

Next hurdle is a J2534 error in ECUflash

 

[onefast2gdsm]

I have the same error in my 1g with a blackbox. I posted a thread no replies yet. My issue is with evoscan though. Ecuflash works fine.

 

[mac 108]

I saw in one thread where a guy tried a bunch of different fixes then tried a completely different laptop running Windows XP and got it to work.

I'll keep this thread updated as I go. Good luck to fixing yours.

 

[mac 108]

Haven't gotten my laptop connected yet, but I did scan it using my code reader.

Pending codes:
P0110
P0100
P1500
P0105


Are these typical codes for the swap or do I have problems I need to sort out?

 

[AllanL]

disable or enable periphery bits?

 

[mac 108]

Alright so here's what I have so far:

I still cannot connect with ECUflash. I always get an error.
I have tried several different models under the vehicle choice and none work. I know it's a stupid question, but which one is the right selection for a 98 blackbox ECU? I assumed it was 2nd Gen/Evo5-6 MH7202F 1996-2001.

I can get EvoScan to connect, but only with OBDII 96-05 selected. If I choose any of the Mitsu specific options on EvoScan, I get the J2534 error.

Also, based on the brief look at EvoScan, I'm getting no readings from the MAS which would explain at least one of my trouble codes. I've already tried a different MAS, so is it safe to assume that the problem is in the wiring somewhere?