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Hybrid TechnologyUnique topics related to the 2004 -2009 RX400H model hybrid drivetrain and other features/options found only on the RX400H. Please use the main forum for discussion about shared components with other second generation RX models.
The repair shop called this morning. He was able to clear the fault code and start the car and everything seems normal. But he's going to keep the car until Monday and run more tests. Thinks it's either the 'hybrid relay sensor' or the hybrid battery itself.
Of course I know nothing about fixing cars. What do you guys think? I think even if the hybrid battery died, the car would still run on ICE alone, right? In my case, the car would not start at all. My friend says he can get a refurbished hybrid battery for $600. I think my next car will not be a hybrid, at least not out of warranty.
I think at 15 years and 200K miles the car and battery have done well...hopefully you're back on the road soon. I would not let this put you off a future hybrid though...things do age and wear out eventually.
How was the car towed? Normally AWD shouldn’t be rolled. Rather it should be flatbedded
Check for water intrusion through rear seams around trunk hinge and gas prop. Check rear light cluster and vent behind bumper. Check bumper plastic bolt below the lights.
What were the codes?
This is a known weakness in RX400Hs. If you get regular rain soakings water ingress and subsequent reduction in isolation resistance of the high voltage battery can occur. It’s typically the red hybrid warning triangle along with error code POAA6. That means the big battery has a short.
Dry it all out and seal the leaks and you’ll be back to normal. There is a chance the hybrid battery has a malfunctioning cell.
Make sure the auxiliary battery (the little one in the front) is working properly. Low voltage there and you get Christmas tree dash lights.
Don’t just accept what the dealership tells you. Good luck.
Originally Posted by WolfyLS460
The repair shopcalled this morning. He was able to clear the fault code and start the car and everything seems normal. But he's going to keep the car until Monday and run more tests. Thinks it's either the 'hybrid relay sensor' or the hybrid battery itself.
Of course I know nothing about fixing cars. What do you guys think? I think even if the hybrid battery died, the car would still run on ICE alone, right? In my case, the car would not start at all. My friend says he can get a refurbished hybrid battery for $600. I think my next car will not be a hybrid, at least not out of warranty.
What were the codes?
This is a known weakness in RX400Hs. If you get regular rain soakings water ingress and subsequent reduction in isolation resistance of the high voltage battery can occur. It’s typically the red hybrid warning triangle along with error code POAA6. That means the big battery has a short.
.
The code was indeed POAA6. It happened last Friday, right after a big rainstorm soaked Southern California. I will get it checked for leaks. Thank you!
This is a known weakness in RX400Hs. If you get regular rain soakings water ingress and subsequent reduction in isolation resistance of the high voltage battery can occur. It’s typically the red hybrid warning triangle along with error code POAA6.
A walkthru for a fix with pics for the P0AA6 code may be deserving of a dedicated thread IMHO.
So if you experience a heavy rain storm the water can get into the internals of your Rx400H?? Really?. Lexus wasn't smart enough to deal with rain huh? So the RX400H must be parked indoors and not driven in the rain? C'mon, the car has 200,000 miles on it. The battery has probably seen the end of its useful life ( and an impressive 200,000 miles!) A battery can be replaced for for less than $3,000 with an extensive warranty. Lets not blame it on rain and not having a car cover. My 2008 Rx400H sits outside 365 days a year- no cover- 148,000 miles.
A walkthru for a fix with pics for the P0AA6 code may be deserving of a dedicated thread IMHO.
I will be sealing up the open seams (even pin ***** holes let in a lot of water). It really is an issue with more than a statistically significant number of RX400/300/350 shape vehicles. And I accept the point they're old and may be now more susceptible to wear and tear. Many different cars do leak. But for hybrids there are additional problems.
But complaints about water intrusion have been going on for the last 10 years. I think there are even a couple of bodywork Toyota notices for these models. One of the worst areas are the rear sub bumper vents leaking via the rear (main body) light cluster.
The point being the POAA6 526/612 error codes (HV battery case short) could be the real reason many have experienced HV battery failure. In some cases I imagine expensive hardware replacement has happened, when a cheaper option of a good dry out/ body seal/ contacts clean could have been done.
I found pools of water under the trunk floor. Mopped and dried it all out (put a heater in the car; windows ajar). I have cleaned the drain plugs – even removed some rubber seal bungs to allow more drainage should it fill up again.
It is driving sweetly at the moment. I must still sort out the leak areas – when we get better weather hence raincoat.
Check the source with a good dousing.
So the trim area around the windows could be a problem. But the window should be sealed.
1/ You have to check the rear light cluster (body not lid)
2/ Check the bumper bolts below the lights
3/ both sets of seams around trunk hinges
4/ Seams that run along the roof rack
Is your motor running OK now POAA6 cleared and car dried?
Take a gander at this