Transmission "resistor", does the G50 have it?

[qsiguy]

I've heard some Nissan/Infiniti products have a resistor that can be disconnected to increase solenoid fluid pressure for harder shifts. Does anyone know anything about this mod? I've seen a Maxima that had it done. A WOT switch would disconnect the resistor so during WOT it would shift much harder but during normal driving it was normal.

I'll pull out the FSM and look at that but I was curious if anyone has first hand knowledge of it.

[Jesda]

On my 240 there's a connector next to the battery. We disconnected it for firmer shifts. I think it bypasses the TCU or something.

We did it because the car would sometimes cease to shift because the TCU was burned out.

[96Qowner]

You're referring to this resistor?

zerothread/144134

[elwesso]

Yeah it has it... Since your car has TCS you're going to have to pull the battery out...

See if you can find it, if you cant I'll see if I can find a pic of it on my computer.

[goody90q45]

Yeah it has it... Since your car has TCS you're going to have to pull the battery out......See if you can find it, if you cant I'll see if I can find a pic of it on my computer.

On Q's without TCS it's pretty easy to get to, mounted below/next to the fuse box. It's about 3" long and 3/4" wide. Two 10mm bolts and a connector and it's yours. On Q's with TCS it's a PITA to remove (Jay!) since it's mounted (can't remember for sure) either on the underside of the TCS actuator bracket or below the actuator itself. Have bandaids available.


Modified by goody94q45 at 3:16 PM 12/24/2007

[qsiguy]

Ok, we've established that it does exist. Do any of you have an opinion on whether or not it's a good idea to experiment with it? If I did it would only be bypassed during WOT or at a set boost pressure.

Is this just a bandaid or is it a decent mod for me? Still planning on some transmission mods/upgrades but it would be nice if this would help for the time being.

[elwesso]

I dont think it will hurt anything... Try it and see how you like it.

[sdkhalsa]

There is a thermistor in the transmission that changes the shifting force according to the transmission temp. More forceful when cold. Mine became defective with the result that the shifts were very harsh, probably with the potential of damaging the transmission over time. My solution was to install a pot(variable resistor) set at mid value. Since I live in AZ the temperature is rather hot most of the time, and this solution has worked very well. I think that you could take this same approach but set the pot to a point which seems appropriate. You could actually fine tune it to match the season. As to the utility of this, I have my doubts.

[qsiguy]

Ok, this will be quite easy to play with. Both the fluid temp sensor and dropping resistor wires are right at the TCU in the driver kick panel and will be simple to get to. I did find the dropping resistor and it's not that hard to get to either (see pics below).

Pin #2 (Pink/blue) is the dropping resistor and just needs to be disconnected to disconnect the dropping resistor. I can put a switch on this wire and disconnect it at WOT or at a given boost pressure since I will have a pressure switch on it anyway to engage the methanol injection.

Pin #33 (white/red) is the fluid temp sensor. It looks to be about 2.5K ohms cold (68* F) and drops as the temperature rises according to the FSM. If it shifts firmer at colder temps then after it heats up I'd just have to switch the #33 wire through a relay and add some resistance to make the TCU think it's colder. I think I'd like to research the function of this sensor before I mess with it. Is it shifting firmer when cold from thicker fluid or from the TCU telling it to? Maybe this sensor is just for the high temp safe mode activation?

I think I'll try the dropping resistor mods first. That seems to be able to do just what I need.




Modified by qsiguy at 2:02 PM 12/25/2007

[audiovisiony33]

This resistor pic you post is exactally the same as the one I have in my 97 FGY33. Does this resistor supose to get hot within 10 min in Idle from cold start?When the car is off I got 8.3 ohms when I start the car it became 10.4 vdc.Is it right? Anyone with this experience?

[qsiguy]

Well I've been reluctant to try cutting the wire from the dropping resistor but tonight I did it. First startup didn't show any codes or issues. Shifting is a night and day difference. Every shift is firm and solid. Much better IMO. I'm not sure of any long term effects to leaving it disconnected but so far I think it's awesome. Shifting through boost it was much better.

The second startup I did get the dreaded "Transmission Malfunction" on the dash display but it went away after a second. I still seemed to drive and shift fine so I'm not quite sure what I want to do at this point. I'm wondering if doing the boost or WOT switch to disconnect it only while under hard acceleration would be better.

Is the only purpose for this resistor to make shifting smooth? I'm having a hard time figuring out what this is for if it's not just to make for a smooth shifting luxury car. I'm sure it's harder on the internals and driveline when it shifts harder but should I be concerned?

Thoughts? BTW, I just clipped it at the TCU where it was simple to get to and reconnect if necessary.
Modified by qsiguy at 1:16 AM 7/24/2008