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Discussion Starter · #1 ·
2008 Sequoia 2WD Limited. 120k miles all driven in central Florida. Bone stock condition, zero aftermarket stuff. Came with tow package, transmission cooler, heated side mirrors, and heated front seats. No other options. Replaced battery 3 months ago because it seemed to have died right at the 36 months mark. Drove fine Saturday. This morning, it acts like the battery is dead. Turn the key, starter clicks and dash goes black.

I disconnected it and my multi meter says the battery is 12.6v. So, good battery.

Hook the battery back up and try again. It clicks and goes black. But this time, because the hood was still open, I notice some strange noises. I traced it to the power steering pump. It's making a high pitched buzz. I turn the key to OFF, disconnect the power to the pump, and try again.

Still no start, but now a new high pitched electric buzz is coming from the air intake valve?? ( Think that's what it's called. It's a powered module that sits at the front of the engine right where the air hose from the filter box enters.)

I shut the car off and disconnected that power cable. Then turn it back on and now I have a new noise that sounds like a very quiet buzz or fan on top of the transmission bell housing somewhere. I can't see it or pinpoint it, though. I can only be sure that it's not coming from the starter or alternator.

I decided to try the in-series method of testing amp draw. With the ignition off and the door closed, my meter says I have a constant draw of 180mA, which sounds like double or triple what it should be. But I never tested it before, so i can't say for sure.

I tested voltage drop across every fuse under the hood and in the cab and the only one that showed any was the ECU fuse at .1, which I expected to see, and the "dome light" which jumps by .01 every 5 seconds as the anti-theft light in the center of the dash pulses, as it should.

Lastly, I checked all of the ground wires to make sure they were still intact. I found 6 of them in the engine compartment. They were all in pristine condition, but I'm not sure if I missed any on other parts of the car that I'm not aware of.

So please check my logic here: 3 different modules act up when the car is switched to ON, but never all 3 at the same time. It's highly unlikely that all 3 went bad at the same time (no lightning storms here over the weekend, so that's not it). I ruled out battery and fuses and I don't see how an alternator could cause that error. I think the only thing that would control power to all of those is the ECU. Or am I wrong?

I also can't reconcile the constant draw. Disconnecting the ECU fuse drops the draw from 180 to 160. What's puling 160mA with the ECU fuse pulled? Is that normal?

If anyone has any ideas, I'm all ears. I'n not opposed to replacing parts myself. I just want to be reasonably sure I'm headed in the right direction.

Note: I don't have a scan tool right now. Lent it to a friend who moved out of state. I've ordered a new one that will be here soon.

-Sivert55
 

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Discussion Starter · #2 ·
Update: the buzzing noise is definitely the starter. I checked the power to the ignition switch, through to the relay, and out to the starter and everything checks out, except that it's the same low 9.7 volts displayed on the dash. Other relays in the fuse panel are getting the full 12.6v, so I can't explain that yet. Can the starter short out to the block when the ignition is only turned to the ON position, without trying to start the car?

Also, when I try to crank it over, I get a 40-50mA current on the engine block. I figured that out because it zapped me when i touched the clamp on a heater core hose and the valve cover at the same time. That doesn't happen before I try to start it, and it stops when i shut the ignition OFF.

I no longer think it's the ECM. It's most likely a short somewhere and I'll try to trace it for a while. But I may just have to take it to a professional. Electrical issues are hard to troubleshoot.
 
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