ECU Install Tips

[Mr. Fuji]

I recently replaced the Dinan ECU Chip (pictired below) in my USDM 1991 5-spd with a used OEM chip. I now have a CEL code: the TCS blinks once, and then stays lit, which I think is a code 0- ECM trouble. Also, the car is in "limp mode"- with a high idle and revs capped at 4K rpm.

I'm not sure if I installed the chip backwards (is that even possible?) or if it was messed up when I got it. The writing on the chip didn't make it obvious which way it should be oriented- is it as simple as flipping the chip around?

Does anyone have any advice/tips on ECU installation?

Fuji

[IWantNSX]

reset the ecu by pulling the clock fuse or remove battery cable. if cel and tcs light come back. flip the chip.. i'm thinking it only go in one way. i don't remember. i have prospeed chip in my ecu, then i install oem one back and it's fine.. no issue what so ever..

[Daedalus]

The chip looks symmetric in the pic unfortunately. Usually there is a notch to give orientation and to locate pin 1. I don't recall on this ECU, but usually the board will have text saying where pin 1 goes. Verify the orientation is wrong before changing it. I don't know what kind of damage, if any, a reversed install might cause.

[audax]

If I remember correctly, pin 1 is towards the outside of the board. I'd have to open my ECU to double check.

Sent from my ADR6350 using Tapatalk 2

[Mr. Fuji]

Update: Reinstalled the chip with the notch on the left (passenger) side and she started up with no problems- no CEL, high idle, or anything to report. She runs smooth as silk now.

I would've thought that a detail like this would be in every post about ECU ECM chip replacement but i guess not. Thanks all for the help, and thanks to MJ for the detailed how-to!

Fuji

[dirtbag]

That's pure magic it ran with the chip installed backwards. I would have never guessed in a thousand years. There must be a ROM somewhere it falls back on.

[Mr. Fuji]

To be clear- it ran with the ECU installed backwards- in limp mode- likely due to some redundant ECU arcitechture, but once the chip was installed correctly everything is fine.

I can't believe that more hasn't been written about the notch.

That's pure magic it ran with the chip installed backwards. I would have never guessed in a thousand years. There must be a ROM somewhere it falls back on.