Tron28

Thanks. I appreciate the response. I read that the bypass doesn't correct the cold weather issue. That seems to require updating the ECM with a patch. I guess I can see if I still get the error when it warms up in the Spring. I live in Minnesota.

It is annoying to clear the error, but I have the reader constantly plugged in. So I just have to take 20 seconds to open the app on my phone and clear it.

Acrad

If it is just an updated factory flash from dealer might be worth an hour of labor in addition to the bypass. You may want to reach out to Hewitt Tech. Owner posts here at times.

http://hewitt-tech.com/store/index.p...ct_detail&p=12

HewittTech

I just wanted to clarify since I couldn't get logged in over the holiday to respond. There is no cold weather issue P2445 on the 460, this is only a problem on some of the 05-06 4.7L vehicles.
It is only a problem when driving in near or below freezing conditions and is related to a glitch in the ECM when getting up to on ramps speeds after already driving or idling for a little while.
If it is the cold weather P2445 on your 05 470 the code will only come on as you are driving but will put you into limp mode which is not normal for only having that code show up.
We were able to duplicate this 3 days in a row on our 05 tundra 4.7l using the same drive cycle. Driving low speed for about 10 min and then then in the same spot coming off an on ramp getting up to about 55mph it would pop.
The only fix that we have found is a reflash of the ECM. There used to be a service bulletin with the re flash for this which i found on TIS but didn't print it out and it has since been archived or deleted.
We have had a couple of service techs who knew what we were talking about and able to find the flash and fix the problem but to date we have been completely unsuccessful in getting them to share the info.
If anyone ever has the cold weather issue and can get the cold weather service bulletin or re flash codes please let us know so we can help others.

Most of the time if you take it to the dealer they are just going to say you need to replace the parts. They will not bother with it being just a reflash or spend the time looking.

Tron28

Thanks for the info. I guess it is just coincidence that the error on my 2005 GX470 started occuring for me when the temps dropped below freezing. I get the error at startup of the car. It doesn't happen while I am driving and/or accelerating. It looks like the bypass may be a good option for me. I might wait for the temps to warm up though before I try installing it as my garage isn't heated.

GX4602011

2011 @ 55K miles. Still under the CPO warranty so no out of pocket expense.

From service invoice:
Codes: P1603, P1604, P1605, P2442.
Both banks of switching valves replaced as well as the secondary air injection pump.

HotKoolaid

Recently picked up a 2011 one owner GX w/ 88k miles. The car appeared to be dealer maintained but when I got the PDF of service history there are a few things I don't quite understand. I have yet to contact the service center where the car was worked on, but rather got the information from my local Lexus dealer. I will try the other dealership next

For starters, what all is involved in a "world class inspection" and how do I get any notes taken during this inspection. Also, the secondary air pump and both valves were replaced on 5/25/15 at 53k miles. I'm not too terribly worried about this issue, the parts look easy enough to access and the repair seems pretty straight forward but I was interested in knowing if the parts used are updated part numbers or if they are the same as the ones that were original to the car. Air bags were done on 11/10/17, two weeks before I took possession of the vehicle, so that's nice. Seems like the owner complained of tire balance issues but I've put 300 miles on it in the last week and haven't noticed any vibrations whatsoever.

Any time I buy a car I always replace all the fluids right away, but it sure would be nice to know if Lexus did an engine oil change as well as service all three differentials before I change it myself. It doesn't look like this truck ever towed a trailer based on the fact that the inside of the factory Lexus hitch did not have a single scratch on the powder coat. I'm not even sure if the Lexus dust cap has ever been removed. I will be towing a small boat with a gross weight around 1,000 pounds, and I want to make sure this truck runs without too much fuss for another 100k miles.

Everything else looks pretty good. Tires are new. Pads and rotors look to be in fairly new condition. All the bushings I can see easily look to be in good shape. Outwardly I can't find anything wrong so I'm confidant this will be a good vehicle.

tecman

Congrats!!

They did put a cover over the new pump to keep water from getting inside but I think every thing else is the same. I have no confidence in the replacement parts so I put a bypass kit on mine.

HotKoolaid

I'm not sure abut a cover because I have never seen another one so I don't have anything to compare it to. I looked into the bypass but even at $350 I think I can repair or replace the parts for not much more money. Lexus wanting several grand for something so easily accessed and replaced makes zero sense to me. It's hard to imagine where they get that figure for the repair.

I did order an external filter that I think will work for the air pump so I can remove the internal foam filter. If I open up the pump and it passes a visual, I'm probably just going to let it ride.

tecman

Here is the filter many are using here.
https://www.clublexus.com/forums/gx-...ke-pump-3.html

Acrad

They probably didn't change the diff fluids... and even less likely on the transfer case since the OEM fluid is around $50/quart.

Here are some maintenance threads you might be interested in.

https://www.clublexus.com/forums/gx-...il-change.html
https://www.clublexus.com/forums/gx-...id-change.html

tecman

10 days now with the new bypass installed and no problems so far.

HotKoolaid

$50 for a quart of 75w is absurd. I went ahead and did the diffs this evening since I already had everything. Checked the center diff fluid, and it looks really clean so I'm going to leave it until it spring.

As a former Jeep enthusiast and daily Volvo driver, I'm super impressed with this truck. I was a little concerned at fist about paying a lot of money for a 7 year old car with 88k miles but we will see how it goes. It appears to be well cared for so I don't anticipate any issues. It was actually the same price as a truck one year newer with less miles but the former had 3 owners and an accident repair.

Waiting to hear back from the Lexus dealer that handled this vehicle most frequently. I sure would like to know the results of the mysterious world class inspection they claim to have performed.

Acrad

Keep an eye on the water pump. That seems to be a more common issue than normal on these Toyota V8s.

IMO...the "world class inspection" is just a quick glance. Mine passed through with a leaking water pump so not too thorough. I fault myself for not seeing it sooner and was there at purchase time. It was repaired under my factory powertrain warranty though.

HotKoolaid

Is the water pump something that needs to be done when the serp belt is changed? I went ahead and ordered a serpentine belt and tensioner. With my type of driving I will roll 100k miles around this time next year. At that time I'll go ahead and do the belt, tensioner, water pump if necessary, and service the transfer case. I really can not think of anything this vehicle needs. All the ball joints appear to be tight and in good shape. Pads look new, rotors look good, tires are new. There isn't even a whole lot of road junk under the car. With the seat bolsters in such good shape I tend to believe most of it's 88k miles came on the highway.

Acrad

It certainly wouldn't hurt as a preventative measure if you were doing the work yourself. I've seen failures form 10K miles to a more normal 200K miles on the Tundra forums. I did see you really want to stick with the pink coolant though.