P0657 code with others. Do I need a ECU?

2003, 4x4, v6, 3.4, std trans. Little bit of a long read coming up.

Backstory. My truck is very much a trail truck these days so it doesn't see much use. Last time I used it was about 3 weeks ago to go pull someone out of a washout. I was in water 1/2- 3/4 up the 35s-nothing out the ordinary for this truck. Drove home and parked it until 2 days ago when we got a snow storm so I had to move it. Battery was too weak to start from not being used/the cold weather I assume so I boosted it with this new Amazon special battery booster my wife got me for Xmas. All went good, started and ran fine.

Here's where the trouble started. I let it idle while I was doing other stuff in the yard to charge the battery. About 15 mins later I hear it running very rough. Get in and press the gas. Nothing. Press it a few more times and it starts to respond but sputtering and spitting out the exhaust running very rough. Throws a CEL. P0341 (crankshaft sensor) and p0351 (ignition coil A primary or secondary circuit has a malfunction). Clear those codes. Start it back up and still running very poor. Cel flickers a few times before it stays on. Another P0341 and this time a P0657 which I can't find in my book. Google tells me it's "Actuator Supply Voltage “A” Circuit/Open" and that toyota FSM says to replace ECU when you get this code. Anyway I clear the codes and leave the truck alone so I can clean snow and do other things.

About 5 hours later I go and start the truck. Runs like a champ. Drive it down the road for 10mins. No issues. All of a sudden it starts again. Barley make it home. Shut it off in my driveway and check codes. P0351, P0141 and a P0300(random misfire). Clear and start again. Now it's running real rough and stalls. Start again and it stalls. CEL flickers a few times and throws the P0657 and P0351 again. So now I start suspecting that it might only happen when the engine is to temp. I wait 1 hour. Truck starts A1 but starts acting up within 20secs. So I let it sit overnight. Next morning truck starts and runs like a champ for 10 or so mins before it acts up. So it's definitely occurring when the truck is to temp and you have to let it really cool down before it runs good again. To me this would eliminate things like chewed or broken wires.

Now for the next strange thing. I go in the truck a few hours later and I see that the CEL and the cruise control light are both faintly lit up in the cluster. No key in ignition or anything.

So this is where I'm at. I haven't really dug into it too much at this point. It's the P0657 code that's throwing me off and has me wondering if it really is my ECU that's fried l, but then again why would it only do it when it's warmed up? I just don't want to go replacing coils and sensors if it is the ECU all along. It almost makes me think that the booster somehow fried it even though that seems unlikely.

Anyone have any insight into that code or what else I should be looking for?

Thanks.

 

I don't know what the problem is. However, if I were you, an ECU replacement would be the last thing I would want to do. I would start inspecting all the grounds, then all the wiring to the cam and crank sensors. hopefully, it's something simple like that.

 

I would suspect corrosion at connectors and or grounds. Low battery voltage during cranking will also cause bizzare unrelated codes to pop too.

 

I just had to get my ecm rebuilt because it got fried. I would start easy and go to smaller things first sensors, wires, fuses and if you need to just take out the computer and take a quick glance inside if you think it could be damaged

 

Did you see inside of yours? Just wondering if I would see swollen capacitors or something. Ecu seems easy enough to take out and inspect.

 

yea well my problem was a burn on part of the board. it was a burn line that basically stopped the connection to wherever it was going.

 

I think first check for voltage drop on your main power and ground wires from the battery, if those test good then check powers and grounds at the ECM. I've attached the engine management wiring diagram and the ECM pinout diagram.

 

Thanks. I probably won't have a chance to dig into it too much until this weekend. I did pull the ecm last night and opened it up to visibly inspect it. Everything looks fine in terms of no water damage, swollen capacitors, etc.