lexpat

Thanks a lot for this link, dadcat. This is exactly the procedure that the foreman showed me. But at that point I couldn't read everything. Now I know that I have to get this procedure performed at my friendly Lexus service everytime the battery voltage drops below 7V. This is really helpful information. Thanks, I really appreciate it.

Just a quick update on my problems, which now seem to be solved. I went back to the service department of my Lexus dealer and asked them for a road test with the foreman of the shop floor. When I arrived there and explained what I believe the problem was, the foreman said that he probably already knows what's wrong with the car and we even don't have to go for the road test. He asked if my battery was dead at some point in the past, and I confirmed it (I once left the interior light on over night, and the next day I couldn't start the car anymore and had to jumpstart it). So he said that the ECM was most likely the problem and he wanted to reset it so that it starts learning again. He also showed me a printout in which one item (I believe it was the ECM) was incomplete when I brought the car in, and complete after they fixed it. He also showed me a service document that listed some of the symptoms that I experienced, and the remedy for it (resetting of or relearning for the ECM). Since then my Lexus is performing well again, and the mileage is up to 28 to 29mpg from 21 to 22. I am very, very happy again with the car, and believe me, I was pretty upset before. I was really happy with the service this time, but I am pretty disappointed with my last 20k service where I had already complained about the same problems, and they told me that they read back the diagnostics and couldn't find anything wrong with the car. I wonder what diagnostics they checked this time. Also last time when I picked up the car after the service and got into the car in the pickup garage, a service reminder popped up on the center display informing that a service (don't remember which one) is due. That also made me think how thorough the service was performed in the first place, and how serious they had taken my complaint that the hybrid doesn't work properly anymore. Does any of you know if I always have to get the ECM reset if I drain my battery? If it has to be done, can it be done by the user or do I always have to take it to the Lexus service?

From what I understand reading this thread, the ICE will run quite a bit after starting in winter to heat up the catalytic converter and the cabin. This makes sense to me. But I believe I have a different problem with my RX400h. I have noticed a few problems since about October 2007: - after I started the car at low but not really cold temperatures (i.e. 30s to 40s) the regenerative braking hardly works. When I look at the power gauge at the left when I step on the brakes, it only goes about 10% or so into the blue area, pretty much no matter how hard I step on it. This percentage will increase gradually when the ICE becomes warmer, but even when the ICE is hot (after 50mls highway) it still sometimes only goes to about 50% or so. And even after this 50mls highway stretch and the batteries fully charged, the ICE kicks in right away when I step softly on the pedal to accelerate. - I also noticed that I used to be able to drive without ICE from my parking garage door to my parking spot (about 100ft) when I return home and the engine is hot, but these days the ICE is always kicks in. Up until October I could accelerate slowly, and as long as the power gauge stayed in the center area the ICE wouldn't kick in. Nowadays it always kicks in, even when I touch the pedal very softly. - My battery gauge always displays 6 or 7 bars. For many, many weeks I haven't seen anything else on the trip info. I only managed to run with the electric motors a little after my return from a long highway drive, and then I managed to get it to 4 bars when I accelerated very carefully. I also noticed that even though it still displayed 6bars (i.e. not green) the regenerative braking is switched off occasionally (even when I tried to brake softly on a smooth road (no bumps)). I understand that it might switch off if the battery is fully charged, but it shouldn't switch off in this case. I would also expect that the battery would then be drained a little by the electric engines to support the ICE while driving and accelerating, but when I look at the trip info it often seems to charge the battery more than it drains it. - The mileage of the car is also pretty bad these days. If I drive in the city with fairly long stretches without braking it is probably around 20mpg or so, even if the engine is warm. I think the current reading since I picked it up from the service is 20.6mpg. I used to achieve around 26mpg before the hybrid parts started misbehaving. I understand if these things happen, when the ICE is cold, but I can't understand why they are happening when the ICE is hot. I had told my Lexus service about this problem when I had the car in for the 20k service, but they said the car is fine and they couldn't find anything wrong with it. After reading all your posts I also tried switching the AC completely off, but that also didn't seem to make a difference. Do you think that my battery already goes dead after 23k mls? I once had forgotten to switch off the interior light and had to jump start the car the next morning. Could it be that some engine electronics need to be reset? I would be very happy if some of you could tell me if you experience similar behavior with your car. Any ideas of what you believe could be wrong would also be highly appreciated. Thanks in advance for your answers.