2000 accord 4 cyl won't rev over 3000 rpm p1381 p0420 p0730
 

Hello,

I've looked at some topics regarding p1381 (cylinder position sensor intermittent interruption) and not being able to rev over 3000 rpm. In more than one case repairing or replacing the alternator fixed the problem. That seems in line with my situation as I've let go this problem of not revving over 3000 for a few weeks now and today while driving I started losing power to radio and AC and dash went out as well until finally the car died and won't crank.

My question is: could p0730 (incorrect gear ratio) be related to this at all? I have noticed some transmission slip occasionally over the last few days. Didn't know if electrical issues would be contributing to that or if my transmission is about to fail as well.

I don't have the shop manual on this computer. A failing alternator can drop the system voltage to give incorrect readings. If you charge the battery to 100% and start the car, what is the voltage across the battery terminals with the engine running?

I don't have a meter, or a set of cables or any other way to fully charge the battery at the moment.

I just got back from a shop and learned that my alternator was indeed shot. They said the stator was bad and is the result of another problem somewhere else causing the alternator charge up too much. They asked if I had an aftermarket sound system with a powerful amp, which I don't.

If not a big sound system, what about anything that's a large electrical power use?

Nothing that I know of. Can't imagine any of the bulbs I've replaced would make much difference. They mentioned that perhaps the battery wasn't holding a charge well enough. This is the 2nd time the battery has been run down to the point where it won't crank. Before my alternator belt snapped and I didn't realize that's what the problem was.

Guess I need to get a meter to keep an eye on the battery when I get a new alternator.

They said it's also possible one or more diodes are bad making matters worse for the stator. I guess that by itself wouldn't cause the problem?

It's unusual, but possibly the battery or the alternator is failing in a way that draws a lot of power from the alternator?

If the battery draws a lot of excess current, I guess that would have shown up when the shop tested the alternator & battery. Or maybe they only tested the alternator?

I just took the alternator out and brought it in. Most of the time I leave early for work when it's dark so I drive often with headlights on.