Forgive my ignorance... Please tell me, what is a TCU?

[AZhitman]

Heather, I'm pretty sure Brian (maxnix) means well, but at this point the eye-rolling and faux exasperation is simply a distraction. He still drives to the dealer for everything.

While I love Dennis and his contributions, he's not the only Infiniti expert in the house. I go straight to Kenny Waun (local dealer service foreman, long-time Q owner, and first Q tech in AZ). Fortunately, he echoes the vast majority of what Dennis says, which means there's a "universal truth" to most of it.

Let's back up, because the namby-pamby ticky-tack bullcrap in this thread is making my arse leak.

Did we already rule out issues with the throttle position sensor?

Why I ask: Unlike Brian, I have actually swapped a couple VH45DE's and spend a great number of hours in the garage building Nissans... so my knowledge will be a little less "academic" and a little more "real-world".

My Q45 engine issue several years ago stumped the service departments at two local, respected dealers, including their so-called "master techs". Their "solution" was a motor swap. The REAL issue was a defective exhaust valve. $20 in parts and a weekend's work later, she ran beautifully for years.

I ran into the same issue, and my transmission DID NOT throw a code. The AT diagnostic is NOT to be relied upon in all cases, and I am LOATHE to believe a transmission replacement RIGHT NOW is the appropriate course of action.

If this were my car, my next steps:

Get ALL the crap out of the trans via mechanical flush and fill. Feel free to drain, fill with fluid, drive, drain again, and refill. You will get enough of the fluid out to make a good diagnosis.

Test continuity and voltage per the FSM on every pin of the TPS (there's a diagnostic chart in the manual).

Get a KNOWN GOOD throttle position sensor and test it on the car. I am still leaning towards this as the culprit.

Please see Steve's post on Page 2 about the DTC thresholds, for WHY you cannot always rely on the AT diagnostic.

We will see you through this. Bear with us.

[heatherin951]

Thank ou very much AZ!

I will do it.

[AZhitman]

Keep us posted. Looking forward to seeing the old gal on my next trip through CA.

[heatherin951]

ummmm.....is "old gal" my car i hope? lol

will report when I complete my to do list.

[maxnix]

Thank ou very much AZ!

I will do it.

Finallly! Someone got through.

Hopefully an engine swap is not required here. But Greg and I both have used the dealer when true expertise is required.

Neither of us use the dealer exclusively. Kind of depends on the condition of your back and the extent of your toolset.

He may be correct on TPS, but not that easy to diagnose unless you have some extra electronics knowledge and equipment. White paper towel test will give you an indication.

Dennis may not know all about the G50, but I'll bet he knows more than anyone outside of Nissan corporate engineering. Very few senior techicians who were trained on the G50 in 1989 still practicing.

[heatherin951]

Hi guys,

I have a question.

How is the best way to get to the two bolts at the top of the bell housing?

Thanks....more later.

[Infinitiguy19]

Good to hear from you again.

But are you having some repair shop the work or an Infiniti Dealership?

The best and only recommended/safe way would be to take the engine with the transmission out as one unit. A LOT of work but better of in the end.

The below is not recommended nor very safe.

Or you can take off the transmission mounts and the drive shaft and see if the transmission drops a little so you can get to the bolts of course with a transmission lift under the transmission.

[heatherin951]

The transmission is being done in my own garage.

I am fortunate enough to know someone who is both qualified and willing.

He wanted to hear from someone that knows about the bolts

[Infinitiguy19]

This may sound like common sense but a torque wrench would make them come out easier its just fitting it in that tiny space that's the problem.

Has the person that is qualified done this before on a similar car?

[SteveTheTech]

I usually do them on a lift but ppastos is pretty much on the money with removing the driveshaft (it needs to go anyway) and once the control level, fluid lines, and torque convertor bolts are removed use a jack on the back of the trans casing and remove the bolts holding the rear trans mount out and slowly lower the transmission. At this point I would remove all the electronic connectors as the are easier to get at now. You will need a long (3-4 ft 1/2" extension and ideally a 1/2" impact gun) the bolts are in there tight and I cannot imagine how difficult this will be on the floor.

Good Luck! ~ you'll need it.

[maxnix]

The transmission is being done in my own garage.

I am fortunate enough to know someone who is both qualified and willing.

Must be nice to have a lift and a transmission jack in your garage!

Your friend will need a 3' extension to get to them.

[heatherin951]

Its done!!! ( We did it without a lift btw...and made a transmission jack, )...I was under there too and bolted it all back together this afternoon. You should see the mess i was. I am not a grease monkey at all you guys... But I spent like three hours under it and I dug it. Im soooo tired, and excited at the same time! I even have a fat lip from a sockett. LOL. So my Q is shifting beautifully. Its finally freaking over!Thank you!!!!!!!!

[AZhitman]

WOOOOO HEATHER!!!!!

I want a Victory Lap!

So awesome - I'm proud of you!!!!!!

[MinisterofDOOM]

Good to hear. It's a huge relief when you know a problem is solved and out of the way.

[Razi]

You're awesome!Glad you got it fixed.

[maxnix]

Way to go! Now get the auxiliary transmission cooler added by next spring.

[SteveTheTech]

Congrats!