I need help trying to figure out what is wrong with my engine. I started noticing power issues and electrical flickering on my dash, headlights, and any lights inside the car. the probably is getting worse. The engine is struggling with power but once I run it it gets better but then the car has shaking or jolting throughout driving. I also seem to have an issue going in and out of 1-2 gear which makes me think there is also a transmission issue possibly.
I was getting error codes for a misfire in one of my cylinders and thought maybe replacing there spark plugs and ignition coil would fix the issue. I replaced all 4 and the misfire code went away and the power did get better. Now the electrical issue still remains. What’s odd is when its cold outside or the engine is very cold I have very little issues. no flickering or little and much more power which makes me think it might be a short related to heat. I had the battery replaced and the alternator is testing great. (alternator is a new one put in 2021).
Another problem which may be realtered is when I’m slowing down my car as its coming to a stop has a really hard shift to first gear and makes a weird noise almost like the piston in the breaks is locking the releasing.
check engine light is on at it says its the catalytic converter. why is the transmission issue only bad when the weather is hot or the engine heats up. also it sounds independent of the electrical problem.
The BCM is the gate keeper that allows communication between other modules in the vehicle, This includes the engine control module, the transmission control module, etc…
If the BCM is unable to allow modules to communicate with each other, all kinds of weird things can happen with the operation of the vehicle.
I asked you to post the codes. Is the ONLY one you see is a P0420? Or are there more? We can’t help you if you don’t supply enough information. ALL of it. Not just bits and pieces.
So I can’t answer your question unless I know what codes you are seeing.
OK, the catalytic convertor is bad, but you knew that.
The P0868 is low fluid pressure, not level. That would seem to indicate a failing pump. Inadequate pressure means the CVT belt slips. Since it is generally OK when cold…when the transmission fluid is thicker… the pump can keep up, more or less. When it heats up, the fluid is thinner, the pump has difficulty building pressure and the CVT belt slips making MORE heat and causing more problems. For sure change the fluid, it is way overdue.
And then there is that P0725… This is an engine speed error code. The engine speed is the crankshaft position sensor (CPS). Apparently this is a common symptom of a failing CPS in a Nissan. They are cheap so I’d just replace it and see how the engine and transmission reacts.
Given how poor these transmissions are, I’d suspect that is the bigger part of your problems.
A service bulletin I came across. when the fluid heats up above a certain temp threshold it goes into limp mode. It is probably why when the vehicle is cold it preforms better. when it heats up it goes into limp mode.
A Continuously Variable Transmission (CVT) is designed to go into fluid temperature
protection logic mode (“fail-safe mode”) if the CVT fluid temperature rises above a certain
threshold. If the CVT goes into fail-safe mode, engine performance is reduced. Customers
may report this condition as “low power” or “reduced engine performance”