Catanzaro

A little history first. The car sat for a few months.

The first time I noticed this was Saturday after sitting for 4 months. On the way home, the lights were on, and heated seats, etc. The car does this intermittently, but only when I have the fog lights, lights, front and rear defroster, heat, heated seats, etc. (not all at the same time, sometimes only a few items on) whether at idle or even driving on the highway for some time.

This morning, the car was fine. Because it was daytime, I only put the lights on as a test. The windows started fogging up, and I was in stop/go traffic for about 7-10 minutes. Again, only under extreme load, and it eventually after a few minutes goes away and never comes back. I have to charge the battery as it may just be weak at this point.

Catanzaro

I found a part # Denso 210-0509 Lexus RX300 Alternator. Amperage = 130 Voltage 12.0 amps. Want to make sure I am looking at the right one. About $200-225 here or there. This place - Parts Hawk is out of stock. It looks like a lot of these are on back order & out of stock.

LeX2K

I have the Denso 210-0466 in my ES this is the 130 amp unit. There are apparently other Denso alternators that are the same but different part numbers. Make sure get an actual Denso, some listings will say Denso but if you read more closely they use the name as a reference but the alternator is not a Denso.

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Catanzaro

Did you have the same issues, or did you upgrade for other reasons? Thank you.

Not bad for $147.79 (+ Tax) & Shipping (Core is $57) on Rock Auto

LeX2K

I upgraded specifically because of flickering it went away 90%. Apparently replacing capacitors in the ECU fixes it completely that's on my to do list.

Catanzaro

Wow! There is a high probability that upgrading will not get rid of the problem in its entirety. Again, this is only happening under extreme stress of all the electronics being on, and not when they are off.

Questions:

Do you have any idea where the ECU is, the part #'s, and what is involved?
Any danger in driving with flickering lights?
When you say 90% of the time, when does it happen, and under what conditions?

I am also assuming that your issue just happened without adding any crazy extra electronics to your car at one point in time. Thank you for your time.

LeX2K

ECU is behind the glove box. Replacing caps requires experience doing board level repair. I have not opened the ECU yet to get the exact component list.
No. But the car runs better with the upgraded alternator the engine has more power.
Flickering is 90% reduced, it happens all the time.
My car is bone stock.

A bit of a warning, if you do pile on a bunch of high current stuff like massive amplifiers it is possible (or even likely) you'll blow the alternator fuse since your new alternator can easily exceed the fuse rating of 100 amps. Under normal use on a stock car it is not an issue.

Catanzaro

The flickering was that day with a weak battery (I guess). Every single electronic was on, raining, wipers, heated seats, rear defroster, front defroster, heat, headlights, fog lights, etc., and probably too much load given the state of the battery. I have not driven in the rain or at night as I have other vehicles.

LeX2K

Apparently the caps go bad (common) I first saw this mentioned by CL member Arsenii and since this guy knows his stuff I'll take his word for it. The engine definitely runs better with the upgraded alternator I noticed it right away. Theory is the flicking is caused by injector pulse load, weak capacitors make voltage spikes worse.


I'll be replacing them with the identical caps unless someone can point me to better ones.

Catanzaro

I guess this is the reason why this happens intermittently from time to time. There was one morning in the dark for 50 minutes that it did not happen. Then sometimes, it just happens. I guess the injector spike load creates this type of environment and this makes all the sense in the world.

Thank you for everything. This is just annoying. One can chase this issue and may never fix it completely, especially if the ECU is all part of this.

LeX2K

I'm going to find out. Could be a while I have a long line of cars in my cue.

Arsenii

Hello,

Thought I would chime in as well..

I've got the same exact unit from RockAuto, the only reason for that specific one was that the price was either the same or even lower than a 100A unit. Works well, the only concern is that the belt is a bit of a stretch to get on as the pulley is a hair bigger, but still doable.

Actually, it's a bit more ... intriguing..

It seems like my honorable mention was made from this thread, where I tried swapping the whole ECU for the one off of 2001 model year instead of my 2000 one, and it seemed to help a bit, though the light flickering is still present, as annoying as it is.

As it turns out, it's not the injectors that do it, at least not for the most part, it's the general load on the system that it wasn't thought through apparently, for one reason or another, as my lights can start dimming in unison with the Hazard Lights all of a sudden, not to mention the seat heaters and other stuff..

I already tried a good number of ways to get rid of this flickering, like looking over the wiring, replacing the alternator ... twice, replacing the ECU, I even got some 4 AWG welding wire to replace my Ground leads, nothing seemed to have ever solved the problem. Granted, it is a lot better than what I started with, but it's still present, as annoying as it is. Gotta wonder how they got away with it when those things were newer and still sitting at the dealerships, there must be something that gets messed with time in those cars..

It seems like the worst offenders there, or what is causing the majority of issues for most people, at least for some part after startup, are A/F Sensor heaters ... of all things, as when you take the A/F HTR Relay out, the flickering is barely there, I remember reading about it somewhere and decided to try it out. The thing is that the Heaters are not just powered straight from 12V, the ECU is feeding those with a known, tried and loved by everyone involved PWM signal, but at some obscure frequency, like 2-3 Hz or something like that, hence the visible flickering.

To make it clear, I doubt it has anything to do with actual heaters, it's just that they do have a considerable power draw, and that draw is really inconsistent thanks in part to that bizarre PWM signal. There may be a way to speed up said signal with a separate controller that would get the signal from the ECU and generate it's own PWM at MUCH higher speeds, and it may be an interesting project to tackle at some point when I have time..

Hope this helps and best of luck!

LeX2K

Wow great info thanks for that. Now in the background my brain will be trying to think of a solution.

Catanzaro

Arsenii:

The A/F HTR Relay, The engineers can easily figure something out if they want to, but they will not.

I had a BMW in which the software download had to be reprogrammed from BMW to change the shift characteristics after 2 fluid changes. I can show you the thread, very interesting. Only the engineers were able to send this down.

Very interesting. Car manufacturers do not tell unless they have to. This is why class action lawsuits evolve years later over something we take for granted. Thank you.