Specifics of throttle computer changes in the 1998 NSX

According to the "Changes by Model Year" post here on NSXPrime, 1998 sees a change to the throttle computer. Does anyone know in more detail what these changes were? Did it improve the throttle hang behavior of the DBW system?

side question — does swapping ECUs between NA2 cars require a reprogramming of the ECU for the immobilizer?

Wow I never realized that. My last car was a '97 and I definitely didn't like the throttle-hang behavior. My current car is a '00 and I have not been bothered by it in the same way. The new car is supercharged and has an SOS clutch, so there are other differences though.

francisluu said:

side question — does swapping ECUs between NA2 cars require a reprogramming of the ECU for the immobilizer?

Click to expand...

Short answer - yes. Probably a couple of ways around that.

The straight forward way is to get a new > 1998 ECU and then pay a visit to your dealership (or the rare locksmith who has the capability) and have them use the special Honda programming tool to do a reflash. It would be the equivalent of what they do when they replace a dead ECU.

If you pull a 1998 ECU from a salvage vehicle, take the matching immobilizer control unit. You can send the immobilizer unit out to services who claim to be able to read the code from the immobilizer unit and clone that code onto new key blanks. You would then cut those key blanks to match your locks. I have not talked to any body who has used that service so .......... Even better, if you can get the keys for the salvage vehicle, you can clone those keys on to new blanks and cut the keys to match your car so now you have matching keys, immobilizer control and ECU.

The immobilizer function is located on a small add-in card in the ECU. I have talked to Honda / Acura owners who have said that they have replaced ECUs on their car by just removing that card and jumpering the immobilizer permissive. This gives them a working ECU; but, no immobilizer function. Hypothetically, you may be able to take the immobilizer card out of your existing 1997 ECU and plug / solder it in to whatever > 1998 ECU that you get which would give you a working ECU with the immobilizer function intact and code matched to your existing keys.