S-MODE doesnt work, P2765 Error

[Snek123]

Hello,

I am solving a problem with my Nissan 370Z MT 2012 Sports packet.

Ever since I bought the car, S-MODE has been going crazy. Usually it works for a short time after starting the car and turning on S-MODE, maybe 1 minute, 5 minutes or sometimes (rarely) much longer and then it stops working, the message "WARNING S-MODE" appears on the dashboard and it doesn't work anymore until the car has not been in operation for a long time.

What I have observed and may be interesting or important is that the S-MODE usually works and tends to work for a longer period of time after pressure washing the car - not sure if it has to do with the pressure itself or maybe water getting somewhere, but it seems to definitely have some positive impact on the S-MODE functionality.

When the car was diagnosed, it reported a "P2765 engine error / input speed sensor B" error - something like that.

When the car was at an authorized Nissan workshop, I was told that it would be necessary to remove the transmission from the car and replace the entire "mechatronics" - I don't know if this is correct - supposedly the problem would be to replace only the input speed sensing sensor itself, and replacing the entire system could work at $2000-4000 so crazy.

Does anyone have any experience or suggestions please? Thanks

[phunk]

Mechatronics?? Not on a manual transmission. The manual trans is, well, manual. There are sensors and switches on it, and that's all for electronics.

I have attached FSM screen shots for P2765 troubleshooting. If you need other info let me know. Link here to the sensor itself. Not a cheap one, would hate to replace it until confirmed bad. Maybe borrow one from a friend. Never heard of this sensor going bad. But these cars are aging now. Inspect the connector and wiring for damage from road debris.

https://www.nissanpartsdeal.com/part...935-cd80a.html

You can swap this sensor in 15 minutes yourself. Its just on the side of the transmission near the rear. Left side I believe, under the shifter area.

[phunk]

3rd page. can only attach 2 image per post.

[ZoomZ]

Ya check the sensor and harness/wiring first. As stated in FSM

[Snek123]

Just a new thought: if the input speed sensor on transmission was faulty, wouldnt S-MODE actually stop working completely and never work? Because it doesnt work most of the times, but like 5 % of the times it DOES work. Doesnt that mean that the sensor must be OK then?

[phunk]

Originally Posted by Snek123

Just a new thought: if the input speed sensor on transmission was faulty, wouldnt S-MODE actually stop working completely and never work? Because it doesnt work most of the times, but like 5 % of the times it DOES work. Doesnt that mean that the sensor must be OK then?

I got your DM but had a long day and just got done working, will respond tomorrow.

A sensor or other electronic devices can have an intermittent failure. They can work 99% of the time, but that 1% they dont, it trips a DTC and that codes remains stored until cleared. (I think some codes can timeout after enough cycles of not having a problem, maybe, but I dont know much about that because I would proactively clear codes and remedy the situation right away).

Intermittent issues can be a result of the sensor itself being on its way out for various reasons... maybe there is cracked internal solder joint or something or really who knows without investigating it. Usually its a better use of time to just replace a part and not worry about why it failed. There could be wiring that was damaged and occasionally drops signal with the sensor depending on which way the wind blows, etc, tripping the DTC.

Sometimes sensors are redundant and vehicle systems can default to another means. For example the ISS sensor should just match the engine speed sensor any time the clutch pedal isnt engaged. Do they have the software coded to revert to engine speed signal when the transmission input shaft speed sensor signal is missing? No way to predict the logic... could unplug the ISS entirely and see what happens, otherwise the guy who coded it might be the only one who knows off the top of their head.