300ZX Z32: ECU Swap

[dickie]

Swapping the ECU:

Installation is simple & takes about 15 minutes to do.

1. Disconnect the negative battery terminal & make sure that it can't reconnect.

2. Remove the passenger side floor mat & peel the carpet from the top of the firewall down. It's held on with some velcro to a wooden panel



Remove the 4 bolts holding the wooden panel to the firewall & pull it out.



3. There are three bolts holding the ECU's mounting bracket to the firewall, remove them to 'flip' the ECU out of it's hiding place.



Unscrew the bolt holding the blue plug into the side of the ECU, this should free up the ECU & mounting bracket.



4. Remove the 4 screws holding the ECU in the mounting bracket. Exchange ECUs & reverse the steps to re-install. NOTE: Make sure that the blue plug is seated evenly all the way across. Just because the bolt is tightened doesn't mean the plug is seated...

Here are some other views of the inside of the ECU if you should ever have to switch chips out:

NOTE: ***Before doing anything to the inside of the ECU, make sure you understand ESD. ElectroStatic Discharge is a killer of sensitive electronics. Your body is capable of storing enough electrical charge to toast certain components. If you own a grounding strap, use it. If not, make sure you hold onto something that is grounded (you basically want to shock yourself on something other than the ECU!) to prevent ESD.***

This is the inside of a '90 model ECU. There are some differences from year to year. The second board hides the modified EPROM



& must be unscrewed to swap it out, it's attached to the main board by a ribbon cable. 'Flip' it over to the side, exposing the EPROM



The chip with the white sticker on it is the JWT EPROM. The EPROM comes out by gently pulling from the two ends that don't have pins coming out. Be EXTREMELY careful when doing this to pull the chip straight up, otherwise it's possible to bend or worse yet, break off the delicate pins! When placing the chip in the empty socket



make sure the end of the chip with the 'notch' in it is toward the end of the socket with a notch too, you can also look for the trace numbered 1 coming out from under the socket on the board. Because I was already there, I took off the back of the ECU



to look at the quality of JWT's work... first class!