ECU's

[mikes94q]

can anyone tell me the difference between the 4J and the 4E ecu? And can you swap them out? Thanks

[lino]

Post the full part numbers and for what car you want to use it on.

[Q451990]

Post the full part numbers and for what car you want to use it on.

Ditto.

There are two part numbers for each ECU. The JECS number, and the Nissan number. The JECS number will look something like A18-B13 P81 - and the Nissan number will look like 23710-68U15.

[mikes94q]

the 4E is B16 P93
the 4J is B20 P97

it a 1994 q45

[mikes94q]

i think that both are no option ecus from the 94 same engine, but I think the b20 is for a california emissions, and the b16 is federal. Not sure if this will effect anything. I got it all installed and the car now has spark but will not start. There is gas, and spark but no start????? not sure whats wrong now.. going to check the egr. I know that the cps is good.

[goody90q45]

There's 8 ECU's for a 94 Q
Federal and CA, both have:
Base (no option)
Active
Traction Control
Active and Traction Control

A18-B16 P78 is for a 94 no option federal emissions
A18-B20 P82 is for a 94 no option CA emissions

I'll PM you the entire Infiniti list

[goody90q45]

the 4E is B16 P93
the 4J is B20 P97

it a 1994 q45

Something's not right here. I'm reading off an ECU list from Jim Wolf Technologies compiled for making their chipped ECUs but for the Q45 it stops at 1994. There's a pattern from the progression of numbers from 90-94 and the two numbers you posted look like they could be from a 96.

If anyone would like the list (all Infiniti/Nissan) send me an email and I'll get it to you.

[mikes94q]

yeah I pulled the ecu from a 94 at a upullit yard. Not sure that it was the original or was replaced at some time. The other computer I have no idea either it was in the car when I got it.