My auto trans in my 02 is starting to shift less than smoothly. It shifts really hard from 1st to 2nd when its cold...especially at high RPMs. I have done some reading and it looks like I should try a new Transmission Control Module(TCM) before I spend the ~$1600 for the trans place to put a used trans in. Any idea how much they go for? Is the TCM integrated into the ECU or is it a separate box? Anyone have success by simply replacing the TCM. And I have ~98k miles so its definitely not covered under warranty.

 

You should let the car warm up some before revving to high RPMs. My 00 also shifts poorly from cold, especially if i start gunning it before the temp gauge begins creeping up. Is it shifting hard from 1st to 2nd even when you are gentle on it or waited till its fully warm?

 

ur car will shift poorly, reagrdless of wat make and model it is, u must wait for the gears to lubricate and at least warm up 5 mins brfore u rev it high, if ur problem was relatedto a tcm ur o/d light would blink 6 times rerally fast. a tcm is a whole different electroni computer unit itself.

 

Tranmission is protecting itself by shifting hard. Cold ATF and low line pressure shifts = massive slip.

 

$500 bucks for a new TCM... it is separate form the tranny. I t is located under the dash behing the cigaratte lighter....

 

I've got a TCM for you if you need one off an 02-03 Maxima. It'll save you a boat load of money. Shoot me a pm if you'd like it. Thanks.

-Paramy

 

Do you have a SES light that indicates a TCM fault code? I would replace it until you determine that. You might try servicing the tranny. It may help.

 

Once it warms up the hard shift at redline goes away. And my O/D Off light only blinked after a did a huge white smoke burnout about 3 years ago. The car wasn't shifting right so I shut it off and when I turned it back on the next time it blinked at me about six times. Took it into the dealership to have em check it out but no fault found.

 

You should first determine if your issue is electrical or mechanical. If it is mechanical, a new TCM will be a waste (unless the mechanical issue was caused by an electrical issue). Find a reputable transmission shop in your area and pay them $50-$100 to diagnose it. Dont go to a regular mechanic as most of them do not have the tools, nor the knowledge to diagnose a transmission and will most likely sublet the work to another shop.

My car shifts crappy when cold, but shifts are okay when warmed up. I took the car to three different people:
Standard Mechanic: Wanted money to replace trans (couldn't tell me exactly what is wrong, whether all parts or just worn parts will be replaced, etc.)
Dealer: No issue with trans
Transmission specialist: Line pressure is 10 psi lower than it should be. Suggested that it is not worth fixing now as I can still get a lot more life out of it.

 

I Find these tranny's are finicky. The 4spd autos seem to have quite a few issues, especially when mated to the 3.5L. The L32 altimas pre 06 with the 4AT have pretty much the same issues we have. Go figure?

I have slip on a 2-3 shift, and hanging on the 1-2 shift under WOT.

Narrowed it down to either, TCM, Shift solenoid, TCM or clutches. Its so hard to tell, its been slipping for like 18K miles so the clutches are probably toast, so they would require replacement..but to figure out why it started slipping who knows.

Contemplated the 6spd swap, but due to a lack of parts, time for a new car (G37 Sedan)