Compressor feedback signal.

I believe it is used to tell the AC AMP of the newer cars that the compressor has been shut off by the ECU

 

Dude, I seriously don't know how to put it in simpler terms. The ECU gives a ground signal on pin #30 to cut the a/c off based on the factors I stated earlier. The only difference is that in I35's the ECU sends that ground signal to the a/c auto amp which removes the ground signal from ACRLY's coil, and the compressor turns off. Since you don't have the I35 a/c auto amp, you have to put a relay in between ACRLY and the compressor so when the ground signal is sent, the relay will cut the signal. Two different ways of doing the same thing.


And no need to get defensive and brag about your wiring prowess. If all the a/c functions were wired in completely, you wouldn't be having this issue.

 

The FSM makes no mention of this signal. The ECU has no way of knowing whether the clutch is engaged or not.


Furthermore, I'm not quite sure how "ACPDCUT" translates into a feedback signal. Cut means cut. This also coincides with the AC cut function the FSM describes in the EC section.

 

Thanks for clarifying it for me.

And thanks for pointing out that I am "bragging". Your tone has been condescending from the get go.

But anyway putting up with your crap attitude has helped me understand what I need to do. It makes perfect sense now, all I have to do is put up with a little crap from certain people and I eventually get the info I need!

 

Pg. HA-34 of 2004 I35 manual.

 

I guess that happens inadvertently when I don't feel like people are willing to read my posts thoroughly. Apologies. I was just trying to help you get to the bottom of this.

 

really I appreciate the help. I read about this from eng92 but never followed what he meant.

I plan on using a micro relay connected to ACPDCUT to intercept the ARCON signal and open the circuit. Now I can see I definitely over revved my compressor, ooops. No bragging here dude!

 

Just read it. I stand corrected. According to the table that signal only applies when the pressure sensor is disconnected, aka not during normal operating conditions. This would be the equivalent of not providing a 1.0-4.0V signal to ECU pin #81. In that sense, it's a bit of a misnomer.

Under normal operating conditions and for all intents and purposes, there is a 0V at pin #8 on the a/c auto amp.

 

Sounds like a plan.

 

is it worth it to swap out the 3.0 for the 3.5?

 

nope. i heard it actually makes you slower.

 

The 3.5 is so much heavier than the 3.0 that I really don't go any faster now. And the 3.5 piston rings go bad in like 10-15K miles. But it's always cool to say "mine is bigger"

 

who was it that actually was saying this before when contemplating swapping in a ka24T...i believe the words were "i dont want to swap in a heavy vq35, rather go with a ka24"

 

"i dont want to swap in a heavy vq35, rather go with a ka24"

 

ooo ooo i found it http://forums.maxima.org/showpost.ph...4&postcount=10
just a little more humor for this thread

 

my question is ...does anyone have a full 3.5 swap with 100% no CELS ?

many states require 0 CELS

 

I have been CEL free for about 1-1/2 years now. I also passed my tailpipe emissions test this past May.

 

haha, i was ~15 seconds away from posting "eng92 is CEL free"

 

How do you bypass the CAN codes? My TCM and ECU are both reporting CAN errors.

Fortunately my car in WA state can just be tail pipe sniffed because Nissan sold some vehicle in 97MY that did not have OBDII. But anyways, I'd like to know how to clear my CAN codes

 

There is no CAN in an ecu for an A33B-6MT

 

Hmm, OK, good to know.

 

you cut the wire from the ECU to the SES light

 

uh have a right to hide after that statement yes....

 

Well i brought the car back home and attempting it myself. so far i "decoded" the wiring harnesses for both the VQ35 and body harness for my car so it's jus to connect up which i doing next week. i jus hope the guy didn't lock my ecu as he attempted to "initialize" the nats system to re-program the original key, don't know why he did that!!!

It appears my car did not come with smart entrance, instead it had the time control unit for thing like the interior lights and warning chime. not sure how it will impact with the rest of the system. have to connect all the harnesses and then see.

 

you may still have a cel cause the ecu will "look" for the auto tranny cause you have a auto body harness.

edit: nevermind im thinking something completly different.

 

do you mean the a33b ecu/harness you picked up your car as it was before the swap? cause im pretty sure all us spec 5th gens had smart entrance, def all 5.5 gens. but i dont know about overseas 5th gens

 

Bro, it should not matter. I am not 100% sure, but I don't think anything in the swap (the why I did it) would require any changes to SEU or time control. I mean, yeah the NATS outputs to the security LED, but that is in parallel. Maybe your PNP stuff interfaces with SEU, but you should be able to get your car running without much to do with the SEU/Time control.

 

That is actually Plan A right now unless I can "get lucky" and find a way to terminate my CAN lines.

Last time I did emmissions, I had my SES lamp (A32) disconnected and the tech notified me that my OBDII system was reporting a "not ready" condition (I had blown O2's) so I played dumb and they went ahead and roller tested the car and passed me anyway. We'll see what happens, I am not sure if the CAN codes will create a emmissions problem, and if it does I just need to convince them to roller the car.

 

Check your State's requirements closely. In WA State, they require no CEL if they are going to perform the OBD ONLY test. If you have a CEL, they allow a tailpipe test, from the WA web about emissions:
Q: What’s the difference between the emission test on a vehicle with OBD and one without it?
A: If your vehicle has OBD, the lane operator at the test station will plug in a cable to the vehicle’s computer connection (usually located in front of the driver’s feet) to download emission-related information. This has no effect on the vehicle.
If your vehicle does not have OBD, or has a type of OBD system that has problems with OBD testing, the lane operator will do a tailpipe test. For a tailpipe test, the operator inserts a probe into the tailpipe while the engine is running, to sample air pollutant levels.

WA State OBD Test Requirements

So check closely before you modify your car. You may be able to slide on CEL's as long as you have a clean tailpipe.

 

Update....

seems where i sent the car before the guy did a hack job on the wiring!!! The electrician who came to look at it after i brought it back home asked me if i carried the car by a butcher!!! well after i wired up all the engine control harness, changed around some connectors for the instrument display an so forth go to start the car no "service engine light, no abs light" and well a few other things, like fuel guage didn't move(not sure if it still has gas in the tank to be honest) and some of the AT indicator lights weren't showing up...

Oh yeah security light staying ON when ignition on... so brought a guy with a scan tool to re-program the key thinking that nats disabled the ecu an so forth, only to realise the ecu now powering on!!

mech checked and the guy cut alot of wires on the 2 8-pin connectors by the fuse box located in the pic above, which i was told supplies power for the relays and other main functions. so i now have to get someone to trace back the wiring for the power supply as it's not something i can handle with my limited knowledge on vehicle electronics.

stress stress and more stress....

 

TERRIBLE. I feel bad for anyone that has to pick up this project in the middle.

You do not need to be terribly smart or gifted with electronics/electrical, but a good understanding is necessary. And most importantly, you need to establish a clear procedure/plan and follow every wiring connection thru the A32 (A33A in your case) and A33B FSM's. It's like a religious thing. You have to make sure every wire is connected correctly, and be aware that wire colors change between chassis and often between connectors (especially underhood, there is alot of color changing happening).

MOST IMPORTANT: IMO only 1 guy should handle the wiring from beginning to end. It can get to confusing when someone elses's work is too difficult to follow.

If I were you, I'd start over on the wiring. Whoever tries to pick up the pieces may prefer to just start over.

 

A little birdy told me the ECU will be quite unhappy on 2nd trip about no SES light!

 

What about readiness?

 

SRTs have all been complete since a couple of days after I first started the engine.

 

What State are you in?

In WA we either OBD test w/o tailpipe or just do a tailpipe w/o OBD, even if the car is OBD, but can not be ready. We don't do both.

 

<----------


I would pass both so it really does not matter where I live.

 

Can anyone see any of the pictures posted by made in china?
Is this a result of the "new site"... I know this thread is old but I went looking for it when I couldn't find it in the stickies here:
http://forums.maxima.org/all-motor/4...-progress.html

Maybe it should be added? nismology?

 

I need to update it. I will soon, my imagestation account closed down, but I have all the pics on photobucket.

 

That would be an AWESOME Christmas present to the ORG!!

 

Merry Christmas!

Updates:
The car now has 35K miles since the swap. I drive the **** out of it.

Oil consumption @ 6000 mile oil changes: 1/2 quart

Average MPG: Summer 30.1 MPG, winter 27.9 MPG

Passed full OBD-II emissions recently.

Converted back to A33B pre-cat/4 O2 sensor stock manifolds. Butt dyno says the HP is down at higher revs. This is compared to my previous Warpspeed Y and A32 manifolds. No plan to go back, I like how quiet the car is now.

Never fixed the AC issue, but I have a new A33B AC compressor, and when my A32 AC system finally conks out, I'll be installing the new compressor and lines that have the A33B pressure sensor which I'll connect to the ECU (as it's supposed to be). The AC works fine at anything below 80% throttle.

So far, I have had no reliability issues at all. knocks on wood..........