Kosc300

May I ask what you used to read that the 13 and 19/20 bank batteries were faulty? I have a bluetooth reader that only tells the CEL code using the Torque Lite app on my phone. I've been continuously getting the P0A7F and sometimes the replace hybrid battery code. The battery continually dies after sitting only 4-5days every week. I have to jump it each time to get started. I took the battery apart before and cleaned all nuts/connectors of corrosion, charged each individual battery. Checked the voltage, and they all looked within reason. Let batteries sit for a week or two and they held a decent charge. Reinstall battery hoping corrosion was the problem, but same issues as prior.

There's no way around changing some of the fluid. If you're changing the bearings, you'll have to drain most of the ATF anyway. If you want to be thorough, you can drain the ATF. Replace the bearings yourself. Then have the car towed to nearest Lexus dealer, and have them to do a complete transmission flush. They'll advise against it, but just demand it.

You know you're in limp mode when the car won't go over 70mph. In my case, if I drove for more than 15min, the system would lower max mph to 60, 10min later 50mph, etc etc. Til it wouldn't drive at all. I'd have to pull over and let the trans oil cool for 20min to an hr and then continue driving. I believe Hanes was able to drive up to 70mph the whole time. Both of us were in gas only mode, no hybrid, so the gas mileage was bad. The oil pump controller should be the first thing you check, as its easier and cheaper to replace. You can see our thorough experiences in the first few posts.

Sorry, im at work, so only short replies. 1. No it does not need to be lowered. 2. No. My car went into limp mode to protect the transmission. 3. Yes, my cruise control was not working either.

Awesome job. Just an fyi, after i did the replacement of the trans oil pump, i used a hand pump to put more atf in like most of you. However, i noticed that the transmission shifted a little rougher, and the transition between gas and electric was a bit harsher. I just did a transmission flush at lexus of manhatten for $350 and she's shifting much smoother now overall. The have a tool that can measure the proper amount of atf the transmission needs. The transition from gas to electric is much quieter and smoother now as well.

Awesome photos Giles. I'm hoping you can get a copy of the receipt to show the bearing part number. I actually ended up buying a used transmission a few months ago since my original symptoms were a bit different from yours. My shop checked all of the connections already to ensure electrical continuity. I'm waiting for the weather to warm up before I take the spare transmission pump apart. Will let you know how it goes in a few weeks when i get some time. Thanks again for all your help.

Hayne, glad you were able to work everything out. I'm still slowly struggling with mine. Your description is very helpful, but i dont understand the mechanics of the tranny that well. I'll see if i can send it to my mechanic to figure out. Last week my shop took a look and ended up bringing in a lexus mechanic. They say that while the Aux trans pump was plugged in accordingly, the contacts were not actually touching. This caused my aux trans pump to not work, which in turn caused the trans fluid to heat up. When the fluid got to certain temps, it limited my driving slower and slower until I stopped and the fluid cooled. This was to avoid burning through the trans fluid. They swapped out the plug and the contacts are touching now. The pump is supposedly working, but there must be another issue because the P2797 code is still showing up. My symptoms are closer to yours now, as I can drive fine in engine only (No hybrid), and the car is limited to 70mph. The trans fluid is no longer heating up and causing my car to go into slower versions of limp mode. The above diagnostics and plug change costed me $600 thus far. I'll have them look at the bearing that Hayne describes and hope that is the only other issue. Thanks

Hey buddy, did you get this fixed? I have an 07 with 133k miles and am running into an issue that may be similar. The car runs fine for 10-15min, but then it won't go over 40mph. If I keep driving another 10min, the car limits me to 30mph. I changed out the trans oil pump controller today. But that did not fix the issue.

So I changed out the oil pump controller today and reset all the codes. It was pretty easy. Unfortunately it did not fix the problem. Any other ideas?

Thanks for the advice. I'm actually located in the US. But i looked up the part you mentioned on ebay and it looks like its for the 2013 gs450h. The part number is slightly different. So i'm not sure if it'll work with mine. I'll order at the below site for $350 shipped and take a crack at it. http://www.lexuspartsnow.com/parts/lexus-controller-oil-pump~g1167-30021.html

Hayne, I have an '07 GS450h with 133k miles and the same P2797 code. Lexus diagnostics told me that the Oil Pump Controller Driver is malfunctioned (part# G1167-30021). They mentioned that the part either operates or cools the hybrid system. With it malfunctioning, I'm having the same symptoms as you driving without hybrid. The vehicle starts right up, but with "Check Hybrid System" and CEL Lights both on. I can drive fine for roughly 10-15min. After that, the vehicle goes into limp mode and a few additional lights pop up (VSC, etc.). The vehicle only allows me to drive a max of 50mph. If i keep going for another 5-10min, it limits me to 40mph. Each ~5min after that keeps going incrementally downward to a standstill. If i let the vehicle sit for awhile (1hr), it'll start right up fresh again. Lexus quoted me $430 for the part. If you add labor, tax, and misc screws, it comes to a total of $1156. I can find the part online for $315. It looks like it is located under the hood on the passenger side. Reference part# G1167 below. Have you had any luck fixing the issue?