(Help needed) Q45 /y33 engine bay harness question

[YogiibEARY33]

Anyone know if the q45 2001 engine bay harness will fit a 2000 should be interchangeable right ?

[VStar650CL]

There are 11 different Engine Room Harness part numbers listed for the 2000 model and 10 for the 2001. While most of the numbers do cross between the MY's, if the numbers on the tags don't match exactly, good luck. The only generic advice I can give you is that a harness from a lower trim is unlikely to work on a higher trim, but a harness from a higher trim will probably just have unused connectors and conductors on a lower trim.

[YogiibEARY33]

Ouch , man I really want to keep this y33 on the road…..sounds like Wiring specialties may be my best bet here …. Either that or source a new harness … been also thinking of a 1jz swap or Ls swap . But that’s more headaches with lots of fab work…. Need me a garage buddy lol

[VStar650CL]

Okay, wait a sec, I saw another post and are we talking about the Engine Room (E) Harness, or the Engine (F) Harness? If there's a tag on it, does the number start with 24012 (E) or 24011 (F)? There are only two F harnesses for the '00~'01 MY's, and while they may not be cross compatible, there are only two choices, not eleven like the E harnesses. The tag on an F should be 24011-3H400 or 24011-3H415. Those numbers must match exactly, but if they do, you're in business.

[YogiibEARY33]

So a shop has my vehicle right now AND According to them the part# is 24011-6HN0A , but that pulls up a whole different harness when I search it up? So idk what’s going on there … they must’ve got the last part wrong but we do know it’s a 24011 …. An so what you’re saying I either have a 24011-3H400 or 24011-3H415? (Engine F?)
I gave them the Vehicle Vin where (harness pic above ) is pulled from a 2001 an they said parts # didn’t match up …. This all started because i was getting a P1110/P1135 …. They concluded my harness is fried and my ECU?

[VStar650CL]

That would be really strange to get IVT control codes on both banks with an electrical causation. Those are both performance codes, meaning the ECM didn't get as much advance as it expected when it strobed the IVT solenoids. When that shows up on both banks, it's almost always from oil starvation in the timing cover and not a sensor issue. I'd want to look a whole lot deeper at that before throwing a harness at it.

[YogiibEARY33]

Crazy thing car runs super fine , Already did the most basic things. Changed oil/ cleaned my old VVTS then I pulled the plug and bought new VVTS with new pigtails … would still get a code after my second drive …. So I took it to a shop an they “diagnosed it “ im sure they were checking oil pressure on their fancy scanners at this point I was thinking it was something electrical too. Like I’m saying car runs super great only on start up you hear the chains slap. Most likely tensioners . What I’m assuming happened (3 things).
1) when I pulled the upper plenum to do valve covers I took a lot of connections off must’ve stretched the harness .
2) I pressured washed engine an maybe water got in through the firewall an ran down to the ECU
3) I did install some stupid Govee lights must’ve shorted my Harness ??
I’ve only had it for (1year)3000 miles lol an before it was just leaking oil from the valve covers .
I did get a system to lean code so I had to re do them … when I finally got them right I get IVT Code

[VStar650CL]

I'll repeat myself, it would be very odd for those codes to have an electrical cause. On one bank, sure. On both banks, absolutely not. You have a hydraulic issue. Maybe a blown seal on one of those shot tensioners, maybe a blown out o-ring, maybe a weak pump or even a wrong oil filter -- but something is screwed with the lubrication in your front cover.

[YogiibEARY33]

Been Using Nissan oem Filters …
maybe I’ll ask the shop to do a full BG Engine flush ?
Maybe swithing to 10w-40 will code go away lol ?
Yeah idk how they concluded with engine harness & ECM . Might take to Dave’s Auto Center . For a second opinion…. Better techs there

[YogiibEARY33]

I'll repeat myself, it would be very odd for those codes to have an electrical cause. On one bank, sure. On both banks, absolutely not. You have a hydraulic issue. Maybe a blown seal on one of those shot tensioners, maybe a blown out o-ring, maybe a weak pump or even a wrong oil filter -- but something is screwed with the lubrication in your front cover.

One question for you my good sir ? What is the 2.2 UF capacitor on the harness suppose to do its near the firewall on passenger side ?…. After inspecting vehicle it was really gunked up with grease . Now that I remember …. When I was supper stoned after Valve cover job I went around an greased a lot of the connectors for some odd reason an I remember turning the vehicle on an i had TPS light on .. so I went back and cleaned all the connectors with that other QC spray instead ….an the TPS turned off after I cleared codes

[VStar650CL]

The capacitor is there to "flatten" spikes in the power supply caused by the charging pulses to the spark coils. It's always located on the high side of the circuit that powers the coils. Nissan does occasionally put them in other places as general purpose electrical noise suppressors. The TPMS is an RF system using "garage door" frequencies, so it's entirely possible that without the suppressor, EMF from the coils was making the front tires "hard to hear" for the TPMS receiver.

[YogiibEARY33]

PROBLEM SOLVED
so yeah i gunked up that 2.2 capacitor an the pigtail with alot of die electric grease, i went ahead an went to nissan an just bought a new one an cleaned pigtail.
an the CEL for p1135 an p1110 have not come back, usually the drive to work in the mornings a pending code would show up an then going home from work it would appear as a CEL.i am happy i went back an retraced my steps... ..i have taken it many time to work now an back home with NO CEL

The capacitor is there to "flatten" spikes in the power supply caused by the charging pulses to the spark coils. It's always located on the high side of the circuit that powers the coils. Nissan does occasionally put them in other places as general purpose electrical noise suppressors. The TPMS is an RF system using "garage door" frequencies, so it's entirely possible that without the suppressor, EMF from the coils was making the front tires "hard to hear" for the TPMS receiver.

[VStar650CL]

Great work! Those coils must have been broadcasting RFI noise to every nearby wire, and the IVT's on the front covers both happened to be near enough to be affected. I'm a little surprised if you weren't getting huge static in your radio, but all's well that ends well.

[YogiibEARY33]

THANKS CHATGPT WE DID IT

After 4months of headaches & 640$, started in 4/21/25 figured out in 07/15/25 lol...

CLOSE THREAD

[VStar650CL]

Great work! Those coils must have been broadcasting RFI noise to every nearby wire, and the IVT's on the front covers both happened to be near enough to be affected. I'm a little surprised if you weren't getting huge static in your radio, but all's well that ends well.