Hi,
I bought my daughter a 2004 RX 330. It has been a great car. She came home today and told me the vents airflow increases with acceleration when the ac is on. She says the battery light comes on when it does it and said the dash lights flicker periodically. I checked the battery and it was 12.7V when the car was off and 13.3V when I checked it running. The alt was replaced in 2018 per the service records, but shouldn't it read higher than 13.3 when running? I'm thinking it has something to do with the alt, but the fact that the battery is 12.7 at rest is throwing me. if anyone has any suggestions, I'm all ears. I pulled codes and only got a P0400 which I don't believe has anything to do with the issue. Thanks for any help!

 

Are you sure it was a P0400 and not a P0500? These cars don't have EGR, but I have had a P0500 code before. It comes up every so often in winter when there's some slip detected and the VSC system gets confused and throws a code, which briefly clears up and doesn't return until next winter. You can also get a P0500 when the alt is going out as the VSC system might not get the values it is desiring which throws an error code. I have had a Remy brand alternator on my 02 Highlander not even last me 3 years, so it's possible - and her symptoms are sounding pretty similar to mine. If she needs another alt, get a Denso brand (OE MFR) for a 2004-2006 Sienna it's a confirmed plug & play upgrade and 150 amps of juice is more than enough, even Denso themselves recommends it for longer life.

 

I just ran it again and that code popped up. I thought that was a speed sensor for the speedometer?

 

there is an EGR Valve of sorts on the 2004 RX330. It is called "Exhaust Gas Recirculation Delay Valve", part number 90910-12204. It is also on the 3.5 engines.

 

Does a bad EGR valve cause the issue I'm having

 

It's not showing 17V and climbing when I check the battery when running. Could I have a bad voltage regulator on the alternator? Thanks!

 

The EGR valve is not the cause of the air flow problem, the alternator is. While the battery is apparently in good shape, the alternator is on its way out. The voltage you measured with the engine running (13.3) is too low. It should be between 14 and 14.5 volts. I think most people will see something around 14.25.

Because the voltage output of the alternator is too low, so is the current output, especially at idle. Alternators do not produce full output at engine idle speed. As the alternator spins faster, the current output increases and things like the fan will have more power and spin faster.

You should never have a voltage reading of 17 volts, that is way too high. You would be better off with a dead alternator. 17 volts will cause your 12 volt things (light bulbs, radio, etc) to burn out prematurely

 

, I meant to say in that last post that it's now showing 17v and climbing when running. I'm going to pull the alt and check the voltage regulator and see if it's bad and go from there. Thanks for your input.

 

So if you’re getting 13+ volts when the engine is running, means the alternator is charging fine, pay attention to the battery.
if the ac is blowing stronger when accelerating, check the in cab air filter or in dash condenser may need cleaning when there’s no filter. Also could be a freon R134 low/leak. Have it recycled at a shop.

 

It was over 17v, which pointed towards the voltage regulator. I replaced the alternator and all is good. Thanks for the input.