Hi everyone,

My name is Robert and I’ve owned my 2010 Lexus RX 350 2GR-FE for a year now as a daily driver that I purchased from my parents at 155k miles. Currently has 179k miles. Services always completed on time, oil every 5k, transmission and diff every 50k, spark plugs and coolant, etc etc.

A month ago I got a p0012 code- “check AWD system”, check engine, TC, and a cluster of lights on. Replaced fuel cap, and bank 1 intake VVT solenoids as that seemed to be the issue most people had in forums. Battery voltage tested and good. I did notice mouse poop all over the engine bay, but no nests or damaged wiring. All was well, car driving fine before and after repair. 100 miles later “check AWD” check engine, TC, this time random misfire codes. Spark plugs and coils replaced, light reset and car driving fine. 100 miles later now same thing- “check AWD system” check engine, TC etc etc. this time p0441 EVAP purge flow incorrect, p0455 EVAP leak detected.

Looking for any and all ideas. Car drives perfectly fine, I have driven 1500 miles since evap codes and drives normally but cluster is lit up with “check AWD system” and check engine, and TC lights on.

This all happened after car was parked in a field in southern VA for 2 days, and it rained. My leading theories are a mouse chewed wires (although found no evidence of that), a bad ground wire, possibly water intrusion into electrical or modules.

Need any and all advice! Don’t know what to do and I don’t want to keep throwing parts at the car because I feel it’s something electrical going on and it’s triggering random codes as the car drives fine.

Thanks,
Robert

 

You may have a clogged sunroof drain. Check for water or dampness around both front carpets. The front sunroof drains are not difficult to clear with weed Wacker line. They are at the front corners of the open sunroof. I would try to clear them anyway even if nothing is damp. There are many YouTube videos showing how to do this. it is the same on almost every car.
Then get your battery tested by a shop, not just a voltage check. A weak battery can cause your symptoms.

Then look again all over the engine bay and remove the plastic engine cover to look for mouse debris. Also pull the cabin air filter and look for mouse debris.

 

Your sunroof drains are likely clogged. When that happens, rainwater runs from the roof channel down the A-pillars and into the vehicle interior, soaking some of the electronic modules behind the dashboard on its way down to where the water collects on the front floorboards. The vehicle's ECU panics due to the wetness and begins throwing all sorts of spurious warning lights and codes.

Check underneath your front mats to see if your carpets are wet. If they are, run a hairdryer on them for several hours as well as up underneath the dashboard on both sides of the interior. Once the areas are sufficiently dry again, the dashboard warning lights and codes tend to magically disappear one by one.

You will then need to clear the debris blocking your sunroof drains. Some owners use compressed air to blow them out. Some owners (including me) snake a length of weedwhacker cord or small-gauge twisted wire cable down into the drain holes on top of the sunroof rack assembly, pushing the cord or wire as far as it will go (usually five feet or more).

 

Thank you both for the responses, I will check the drains and go from there. I actually just had this happen with my 2013 boxster a couple months ago that I just purchased and a bunch of modules got wet the first weekend I owned it.

I will also check the cabin air filter and other places for more evidence of mice. Hoping this isn’t something that would require the dash removed to fix, that’s above my skillset.

 

Hi, I recently started having the same issues but with some different codes. My 2010 RX350 has 133,+++K miles and has been running great. Regular maintenance done except the tranny drain/fill because I purchased it with 90k three years ago and i'm afraid to have it done and then have issues. The Toyota dealership where I get oil changes and general service done said theres a chance of issues if the tranny drain is done now. Hopefully not a mistake.
A few weeks ago a Check AWD System message, TC light, Check engine light and a light with exclamation in a yellow triangle, all turned on at the same time like a Christmas tree. Codes showing are P0157 - bank2 sensor2 low voltage, C1201 - ABS/VSC disabled due to a detected fault, C1280- engine control malfunction, U0129- Lost communication with brake control module, and even showed codes B2415 and B124B which have something to do with Automatic High Beam system and vehicle speed sensor. I'm no pro mechanic but I try to keep my cars running as best I can.
All these lights come and go at the same time every week or so. So when I went for an oil change the lights were not on and only code showing was P0157...yes, I scan before/after going for dealer oil changes. At that moment the dealer recommended a new battery.

A few days later, lights came on again. I purchased a new battery elsewhere and lights went off......a few days later back on...a few days later they went off and now are all back on and been on about a week.
Any DIY suggestions?
Or does anyone know a trusted Toyota/Lexus troubleshooting mechanic/shop around the Northern NJ area that can figure this out?

 

I would make sure the new battery is properly charged as they sit on the shelf for months. Also check the battery cables for corrosion and each end. Check it's voltage.
Go for an hour drive and do not use the day running lights. Or better, hook it to a battery charger if you have access to one. Or try a reset and disconnect the new battery for 30 minutes and hope that helps.

I would avoid the dealer for a car this old. They will just make up stuff to sell you.

I would also find a shop to perform one cold drain and fill on your transmission. That will introduce about 2.25 quarts of new fluid, enough to give it a mild refresh, but not enough to stir things up.

Use this link to find local shops recommended by listeners of the NPR radio show car talk. It lets you search by city and state. You can also fine tune it and enter car brand. I would use Toyota over Lexus as it may get more hits and this engine is identical to the HIghlander, Sienna, etc. Then cross check any interesting shops on Google and Yelp for newer reviews.
​​​​​​https://www.cartalk.com/mechanics-files