I have been experiencing some interesting shifting under medium to heavy throttle with my 03 auto. RPM spikes occur at uphill and flat surfaces at 40ish+ infrequently. RPM's rev up with no speed increase almost as if there was a disconnect in the drivetrain. This problem is non existent at normal throttle and only bugs me when I need to pass or get on the freeway going uphill.


I am about to swap the TCM at the recommendation of ORGers, but I wanted to see if there was an actual change in the TCM design over the years. I could buy a junkyard TCM for $130 bucks vs the Dave B TCM at $400+. If there is a design difference I'm all for the newest, but if nothing is different why waste the $$$?


I also added a Hyperground kit with a tranny ground. installed identical to ORGers instructions. Could this be possible playing tricks with the TCM?

Your thoughts?

 

There is also a valve body issue with the automatics. If you are having problems with slipping but the fluid is still pink and doesn't have a burnt smell, the odds are the issue is electrical/computer or the valve body. If the fluid is dark brown and has a noticable burnt odor, most likely the problem is in the clutch packs and that requires a rebuild.

 

Tcm???...

I thought only early model has TCM. if im not mistaken 2000 and above comes with ECM, which means new models comes with 1 computer. unlike the older models they carry 2 computer. which one is right?

 

Thanks SW,

Fluid is nice and red/pink without a burnt smell.

I'm all for the VB mod and less slipping in general, but if I do swap the TCM I want to know if I'm not getting a "old version" vs a newer unit which has less bugs and costs 3x.

 

I'd lay odds it is a valve body issue and not the TCM, which seems to be more of a problem with the 5th gens. At least a few with 5.5 gens have had similar symptoms, swapped in a new TCM and had no improvement. One person did mention installing the Transgo kit and all his slipping problems ceased.

 

I'll look into that Transgo kit.. Stage 1 for sure.. Thanks!

 

Just had a followup question... Would the Transgo kit fix the faulty VB or is it just a mod add on? I found the TSB for the VB so I will start there then work to the solenoids, TCM, rev sensor.

 

Scott was referring to me with the Transgo kit. It fixed my 2-3 slip and firmed up my shifts. I went this route first because I wanted the shift kit whether it fixed the problem or not. I guess I got lucky and didnt have to do any more troubleshooting.

I was just going to post you the thread but it looks like you've already been in there.

As far as fixing the valve body or just being a mod, for me it was both.

Good luck.

 

Sweet. Glad to hear of the fix and shift improvement.. Transgo it is.. There is a distributor out here in Concord so I am in luck.

 

what is Transgo kit, is just a shift kit and what does it do?? thanks

 

Just got the kit $54. Transgo has a local distributor so far so good.. I have the kit at a local shop for pricing the labor. I'm not touching the tranny (no place to work) so labor is going to be steep.

The kit is a collection of tranny internals that replace/modify the internals of the tranny VB. Shifts are firmer and more direct than the stock slop shift.

 

^^ does this Transgo kit requires opening up the transimission? or dropping the pan?

somebody teach me please, my A/T CHECK light is flashing every time i start the car..

 

Dropping the pan is all I believe you need to do to gain access to everything the kit modifies. The valve body does have to be removed.

If I get the kit, I'll have a shop do the work. I've put shift kits in TH350 transmissions but the kit is pretty straight forward. New seperator plate, change a couple springs, remove 3 check ***** and put it back together. Mess up a TH350 and you can pick one up at a wrecking yard for $100. Can't do the same with our transmissions so I'd rather have someone else on the hook for a replacement should they mess it up.

 

So no more cold weather slip at all?

I was reading in the latest Hemming's Muscle Car about a similar problem (cold transmission slipping) in a Ford and the tech writer said that is typically a valve body problem, probably a spring binding. Once the transmission warms up and the passages expand, no more binding.

 

k mine works fine, it's just that the A/T CHECK light flashes for 8 seconds whenever i start the car, shifts normal like first day i got the car(used).

Any thoughts?

 

Have you checked for codes? Mine comes on for a couple seconds, just like the SES light when I first start the car but it doesn't flash.

 

None at all.

1-2 is a bit firm, maybe too firm for some. Ive come to get used to it. Im sure the tech could remedy this by not boring as deep on that valve. I was told to bring it back in and they could close it up some but I said screw it.

 

cant get the code coz i cant do one step in the AT-51.

the light usually comes on like the other ones for system check(only 2 sec), but mine keeps blinking when the other ones are gone(8 secs in total)...

 

My 02 QX4 had the same prob as the OP...the VB and TCM were replaced under a service bulletin and all was well after that.

I have the same prob. I can't manually pull codes using the key/gas pedal trick in the FSM, and my GST can't access the trans codes. Seems I need to PAY someone to scan the car with a CONSULT-II.

LMK if you ever resolve it!

 

how did yours happen?

mine happened right after my new HU installation.

i tried to start the car, but i couldnt, coz i forgot to put it in P position, i had the shifter somewhere else so i could remove the shifter trim.

freaking stealers want 70 bucks JUST to scan for the code, screw that, im doing it myself since there's no change in my car's performance.

 

the FSM says turn the key to ACC, depress the gas and brake, switch the gear from P to D.
mine won't let me switch, when I press the gear **** to the right, there is a click sound inside the dash, I guess it's a key lock. it won't do what the FSM says.

 

^^ yeah that's what im facing too, does yours blink more than usual everytime when you start the car?

 

Mine has been this way since I swapped this drivetrain into my '97.

I've searched this issue before, and I could not find any instance where someone posted that they had sucessfully used the gas/ign key trick in the FSM. Every post I have seen has been that they couldn't get the codes this way.

 

autos have both. tcm is located behind and under the radio. this controls the tranny.

 

there is a shift lock on the shifter. u have to turn it before u are able to switch gears in the acc position.

 

If your AT light blinks more than usual. The TCM is telling you that you have a problem inside the transmission. Once you go into the diagnostic mode. The AT light will give you a series of blinks. I believe its about 11-13 blinks.(cant remember) Certain blinks will be longer than others. Make sure you write this down because whichever number blink it is....thats the problem its telling you.

ex. blinks 1-2-3-4-5------(blink is longer than the others, write 5 down). They're all in the FSM.

 

yep there's a problem.

 

It depends, you might not even have a faulty VB. I would say take it to a tranny shop to get it checked out first. Because if your clutches are worn badly then there's no point trying to put the kit on. Check your fluids, make sure the levels are good and that its not burnt.

 

PM me if you have any questions or need help with the tcm diagnostic.

 

hmm so tcm or entire vb would cause wierd rpm flaring without increased speed/movement in car?

ok if i dont use my car for 2-3 days and i start it, it shifts fine.

but after a hour of driving it will go back into some wierd flaring.

mech said it wasnt the tranny and from what ive seen my fluid is nice and pink/reddish.. same color from when you see it in a brand new bottle of ATF

could it be that in a few days my car forgets its patterns.. and while driving for a few hours it 'relearns' and screws up again or could it be something els? tranny?

 

does it flare in the 2-3 shift?? also, i learned it could be the fluid amounts not correct, voltage problems, bad sensor problems....

 

Now that u mention it vq I did notice my trannys fluid level was alittle low from the last time I checked it about a month ago and the voltage thing could be it as well, as I notice everytime I have my dome lights on and roll down a few windows the dome sorts dims a litlle till I let go of the power window switch... Would you know what to look for on the low voltage thing?
Also like I said before I was at an alright level about a month or two ago and saw my fluid was under level alittle.. Is that normal?
This time though I overfilled just a little so now I'll monitor the levels better this time around.

Vq I appreciate the help cos it really does make sense. aswell as any further advice you may have. I'm all ears...

Btw pardon my grammar I'm on the iPhone with it's fake lil browser

 

just wanted to update back.

today i parked my car and popped the hood to examine the engine bay and noticed ALL of my fluids were pretty low.. i havent changed them since...November maybe.. before it started snowing i didnt touch any of my fluids..

Is that normal ?

I topped them off all to there appropriate levels and even overfilled the tranny with ATF a bit and almost immediately noticed a smoother ride.

I am still trying to find the solution for the voltage problems.. im thinkin of changing my belt (00 max only has 1 right?) and see if that fixes anything, since ive never never changed it since owning the car.

would it be a good idea to change my belt now or try and put it off till the spring/summer?

anyway much thanks to you VqMoNsTeR for the awesome suggestion!

 

overfilling the tranny could also cause slippage. but if u notice a better ride immediately then go with it. do u have a underdrive pulley or grounding kit. those i found to be very helpful with AT's.

 

yea i only overfill because i think i have a small tranny/main seal leak last time my car was up on the lift i noticed some little fluid on the metal shield under the car.. but i don't plan on shelling out money to fix that at the moment since my tranny runs near flawless and i hear its like 500 bucks for put a new freakin seal/rubberband...i know its not easy having machine lift parts out my car..im sure its alot of 'labor' for the mechanic but im just not ready to get robbed...but hopefully when i do get it done ill remember to make sure they use some type of bulletproof sealent before the shut the thing for good.

but for now ill just wait and hopefully itll clog itself up (now thats wishful thinking!)

also vq neg on the grounding kit... i dont..
i dont have anyone to install it for me, so ive never purchased one..
i asked my usual mechanic if he knows how to install a grounding kit and if he would do it for me and hes like he has never done one.. so i wont bother being the guinea pig/test dummy with my car...wit hthat guy but vqm0nster if you know anyone who knows how to do this hook me up bro, no doubt ill pay the person.

hopefully theyre in nyc area though lol

 

I'd have the mechanic take a look at the shift solenoids too.

 

scotty was that for me?

 

No "y" on the end of my name, but yes, dewdy.

 

Oh snap i never noticed that man i always thought it said scottywax :x

my bad and dewdy lmao thats awesome!

ill make sure i mention it though thanks bro <3

im kinda now debating just leaving it as is and saving my money to trade for a newer year maxima or 350z or dare i say toyota this year so im not even 100% if ill end up doing any more work to the car, since im uncertain if im even keeping her anymore. car runs great except for that small wierd problem which doesnt really affect the performance at all its just a inconveniance to me but im sure the dealers will fix that up before re-selling.