I have a 2003 5AT, and am having issues with downshifting manually.

Issue:

When firmly and quickly pulling back on the shift lever in manual mode, the instrument cluster LCD will display the lower gear I am trying to enter, for 1/2 second, then revert to the higher gear I am trying to get out of. Physically, no gear change is made. I think this is due to the quickness of my shift, but it is done firmly and completely, with the computer acknowledging it by the momentary LCD change. I can avoid this by holding the shift lever in the downshift position for inconveniently long period of time (1 second), but that gets annoying.

Situational Details:

• The RPM of the gear I am downshifting into is not unreasonably high - 3500 to 4000 ish if accomplished (but will occur at any RPM basically).

• The shift is made firmly and completely, but quickly

This never happens when upshifting.

I have debated wiring in a circuit to prolong the electrical contact after I release the shift lever, but I would like to fix this properly if I can figure out the problem. I don't like bandaid solutions...

HAS ANYONE ELSE HAD THIS ISSUE?

Thanks!

 

Nope . . . . never had the problem myself or heard of it being a problem. Have you searched ?

 

Isn't there a trans software update for the early years?

 

I have searched, but come up empty handed. Maybe it's just particular to my car. Hmmmm....

 

I have no idea, that would be a great solution. I will call Infiniti and ask. Never thought of that. I'll repost if I hear anything...

Stillen will upgrade your 5AT valve bodies... Stillen, SGP and Level 10 - to name a few. I will do this soon anyway. I would enjoy a sharper tranny, as well as the added capability to handle the higher output from a supercharger.

Note: the s/c is not on yet, so that is not the cause of the shifting issues...

 

You should also consider a good grounding kit...

 

Grounding kit won't make a difference. I had the GG 10 wire kit and it didn't make a lick of difference. My 03 exhibits the same behavior. I've also noticed similiar behavior in an 05 X loaner. There's no real fix that I'm aware of. Basically what is happening is the TCU is seeing that you want a rather aggressive downshift and it is second guessing your intention because it thinks you may have done it accidently. Mine usually does it when I want to downshift from 4th to 2nd.

 

I do have a grounding kit (Gordgee's GG), and its installation hasn't made a difference... I'll build a circuit that extends the electrical contact time 1/2 a second and see if that makes a difference. Ahhhh, to the batcave.

 

Over time I have learned how do shift flawlessly in MM mode. I do find that the downshift into lower gears requires a bit of a longer hold on the shifter. I got used to it. I took real practice to get the "double downshift" to work. Timing is everything. I did have the dealer load the latest TCU firmware and I didn't really notice a difference.

 

I use manual mode all the time and this has never happened. I have an 2004.5 5AT coupe. And for me the grounding wires made a significant difference in the "electronic portion" of the shift (display change became instantaneous).

Sounds like shifts are failing - weird...

EDIT: By the way I have noticed that 05 sedans do not shift like my coupe either. The double down shift goes through the intermediate gear. My car goes straight from high to low gear (e.g. 4 to 2 or 5 to 3) with no intervening step. Another oddity between the tranny revisions (or TCU).

 

i've noticed this too, but also noticed that it only happens when you aren't in the gear you're shifting out of (shifting from 4 to 2, but not giving it a chance t engage 3rd before shifting 2nd), i figured it was design intent, to make it safer and boring...

 

My 03 sedan has never grabbed 3rd if I want a double downshift like a 4 to 2. I don't know what it would do if I tried a 3 to 1, but I never manually grab 1st unless I'm at a stop or going anymore than 10mph.

UPDATE
A couple years ago I adjusted the metal pins that actuate the up/down shift buttons within the shifter unit. You can see the pins/buttons when you remove the console and look on the passenger side of the shift unit. I simply bent the pins so that they would engage the buttons quicker without as much shift lever motion. I had adjusted the upshift pin quite a bit, but not so much on the downshift pin. Last night I adjusted the downshift pin. Now upshift/downshift buttons engage with less a 1/4" movement of the lever. Today while driving, I was trying to get the tranny to second guess my downshift intentions (primarily a 4 to 2 downshift at 40-45mph) and it would plop into 2nd everytime This isn't the norm for my car at all. I don't how adjusting the pin made a difference, but it apparantly has. You might want to try it. Just be gentle bending the pin though.

 

valve bodies or a grounding kit... youll see a difference...louder speakers smoother shifts for sure

 

Update #2

I just got from lunch and drove around with the manual mode modification. WOW! I tried a 4 to 2 downshift at 50mph and it did it. No questions asked. I did a 3 to 1 downshift at 20mph and it did it. No questions asked. It's like a different tranny now.

 

OP, if I remember correctly, I think the 03's (and maybe later years) do not have rev-matching like the 05-06. When you shift, the tranny will shift a little harder and the engine won't match the revs for the speed you are going, in the gear you are trying to shift into. Perhaps there is some safety feature that will not allow the transmission to downshift when the revs will be over redline in the lower gear??

A little OT, but does anyone else with an 03-04 5AT have the issue when you shift into manumatic mode, the LCD display shows "4" instead of the gear you are actually in? You can downshift, but it always starts out at "4". This is so irritating when you are at a stop, shift into manumatic, and it shows "4", so then you have to downshift to "1" so that it will drive like a normal manumatic as you accelerate. My FX is different (aka normal); when I am at a stop and shift into manumatic, it shows "1" because thats the gear I am in. It holds that gear as I accelerate until I upshift. And when I slow down to less than 5 mph, the gears automatically shift back down to "1". Plus it has rev-matching, so when I downshift the gears shift smoothly; there is no jerking like I'm popping a clutch on a stick.

ANY WAY TO FIX THIS/REPROGRAM THIS!?