ok so, first off. i have a couple of different harrnesses.
i was told the one is off of a 92,(bottom one in the picture) and the second one that i pulled, is off of a 93.(top one)

some of the plugs are the same, others are different. now,(such as the CAS) which one should i use? does it matter?
ok, next, can i use this cas on this motor? it appears that the ears on the one on the right are different than the original.... im kinda lost here, i was told that the replacement i got would work on any s1 motor, but its def different.

ok, lastly, here's both ecu's that came with the harnesses. they appear to be able to plug into either harness. now, are they interchangeable? can i send one out to get chipped and switch it out later?


any help and info would be appreciated.

eds13 wrote:


any help and info would be appreciated.

The harness on the left looks to be from an S2 engine and the one on the right is an S1. I am no expert in being able to tell exact differences but in my experience with these harnesses that brown connector is almost a dead give away for the S2 motor. If anyone else knows better please feel free to chime in and correct me.

^i was just told the same thing. good info man!

I think the ECUs are interchangeable.

I can't help on the CAS

The ECU's are interchangeable 90-95.

The CAS with the connector on the top (like in the picture) is from a 94-95 engine. You have to use a S1 CAS in an S1 engine, S2 CAS in a S2 engine, because the head is machined differently. That said, they both output the same signal, so it doesn't matter what ECU you use. Note the 90-93 ECU is preferred because it's easier to program down the line, so don't get rid of it.

The one that you think is from a 93 is most likely from a 94. The 1994 model year started build in 1993.

On the S2 harness, can someone tell me what those connectors close to the ECU are? The Brown, the blue and the two whiteones?
Looking through the wiring diagrams and im going nuts

david.fryklind wrote:On the S2 harness, can someone tell me what those connectors close to the ECU are? The Brown, the blue and the two whiteones?
Looking through the wiring diagrams and im going nuts

Its not that difficult lol Blue is your Power plug, Small White is your Fuel Management, Large White is primarily your guages, and the Brown I have yet to determine what its for. When doing wiring for swaps I dont even pay attention to the brown connector. You could also have an additional small white connector for TCS if your Q has TCS. If I could find a foldout with ECCs wiring much like the FSMs for the 93 and older Qs have on this forum I could give you more info but until then I will continue to ignore it.

Great, thanks mate!

Actually i own a 350z and swapping a VH45 S2, doing some research as the engine came as a long block with harness and ECU (luckily), been looking through the wiring diagrams and harness locations in the service manuals but i was unsure of where these go, not anymore though, unless i fancy bothering about the brown one

Good Luck on the swap definitely interested in seeing the final product.