Nissan Titan Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1 (Edited)
Transmission/TCM Issue - Need some advice

Hi TT, first and foremost, thanks for all the great info. I've been reading/using this site for years and typically I'm able to find the info I need without posting any questions.

This time it's different: I can't find anything that is a definite answer. My previous attempts at fixing my issues have all failed and cost me time and money.

MY ISSUE: no overdrive. Shifts from 1 to 2 to 3 to 4 to 3 again. Repeatable at about 40 MPH. If I manually shift into 4th, my T drives fine. I just have no overdrive.

Vehicle and History: I have a 2006 Nissan Titan LE, 4x4 crew cab with the tow package and 206K miles on it. I used the crap out of my Titan and it's been a great vehicle. At about 165K miles, I lost the transmission clutch and had it rebuilt. I live on a dirt road and the seals apparently failed. Prior to this, I've also replaced the fuel pump and taken my T to the dealer for recalls as needed. I'm the original owner and purchased it in Jan of 06 with 7 miles.

From reading/troubleshooting, I've done the following:
1. Changed transmission filter and fluid - checked fluid level
2. Replaced the valve body - used design 3 though design 2 came standard
3. Replaced all solenoids - again, from the design 3
4. Replaced the throttle body and took to dealer for reset

That's the order in which I've done everything so far but I still have no overdrive. My T drives a little different now but still has great power and can still pull heavy trailers, etc.

My concern and I hope the obvious solution: will the TCM from the design 2 work with the design 3 valve body and solenoids? My guess is the solenoids have different ohm outputs and the TCM may falsely interpret the signals.

BUT, but: I changed the valve body and solenoids to design 3 from design 2 and nothing really changed: other than I spent time and money but still have no overdrive.

My "newest" guess/conclusion: change the TCM. I have the design 3 TCM on hand but I didn't change it when I changed the valve body and the solenoids because the little springs that were on design 2 were not on design 3.

Here's a reference to see the difference between the 2 designs: http://www.makcotransmissionparts.com/mm5/graphics/00000001/RE5R05A-MECHATRONIC-CONTROL-ASSY.jpg design 2 springs in the area that says "verify tcm design" - the yellow arrow is pointing right at the springs.

This one is design 3: http://www.makcotransmissionparts.com/mm5/graphics/00000001/P63740-5-t.jpg the "number 2" is circling the area that does not have springs.

I can easily change out the TCM with the design 3 TCM vice the currently installed design 2 tcm (which I now believe may be my issue) but I'm concerned about the springs.

Back to my original issue: do you think the TCM is the cause of my issue? And... can I install the design 3 TCM as it is?

Oh - to be clear: I am not a mechanic but I'm also not afraid to tear into stuff and try to fix it on my own. I try to do my research but I sometimes get it wrong. :)

Thanks for taking the time to read and respond for my benefit.
 

·
Registered
Joined
·
162 Posts
Who rebuilt the transmission? With only 40k miles on the rebuild I would be talking to whoever built it. What were you doing when it first happened?
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
Yeah, I thought that too so I went to the shop that rebuilt my transmission. He said the exact same thing: it should have lasted longer on the rebuild... but he was going out of business the next day. So I decided not to leave my vehicle with him for fear of it being there for a very long time.

The valve body, solenoids - I did that part myself. Took about 4 hours and watching a lot of youtube videos.

I took my truck to the Nissan dealership and they told me I needed a new transmission.... I'm hoping I really just need a TCM that understands the newer design of valve body and solenoids.

Today, I'm going to take it apart again and put the design 3 TCM in, see if anything changes. At this point, I have nothing else except guessing or taking it to a trans mission shop.
 

·
Premium Member
Joined
·
141,094 Posts
Where are you?
I'd be willing to loan/test you the TCM out of my perfectly good truck for the sake of diagnosing this.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5 (Edited)
That's a very nice offer but I just finished installing the design 3 TCM that came with the valve body. I swapped the TCM, which took a few hours and tried it. Titan works fine!

The TCM was in fact the issue!

Now I have a spare valve body and solenoids that work for a 2006 Nissan Titan. If anyone needs this, send me a PM.
 
1 - 5 of 5 Posts
Top