Hi all,

I have a 2015 ES300H. Current mileage is about 42K. On a long distance driving around Xmas 2019 from LA back to San Jose on I-5, whole bunch of warning lights came on all of a sudden including the "Check Hybrid System" light. Then gradually the car lost power on I-5, which forced me to pull over to the shoulder. After resting on the shoulder for about 10 minutes, I decided to force the engine in gasoline mode by pressing the gas pedal really hard in S mode (sport mode). Fortunately, the car was able to respond to that hard acceleration and I made it home safely by keeping the car in the gas engine mode during the last 100 miles of the trip all while the "Check Hybrid System" was on along with some other warning lights on also.

I brought the car back to the dealer 2 days later. On the way to the dealership, "Check Hybrid System" was still on. But mysteriously, all warning lights suddenly disappeared about 1 mile before I arrived at the dealer. I described the situation to the service advisor. After leaving my car there for 2 days, they were not able to find anything wrong. A month later, I brought the car back to the same dealer again. But they again said they were not able find anything wrong.

Now, the car drives fine. But I always worry there is some issue with the car that can pop up again anytime. This makes me worried about taking this car on a long distance trip. Ever since this issue happened on I-5 during the drive home last Xmas, I noticed that during freeway driving, the hybrid battery power bar has not been able to get above 2 bars. It always stays low at 2 bars or lower. However, once I get off the freeway and onto the surface streets, the hybrid battery power indicator started to increase to 7-8 bars as before. So I suspect the problem is not the hybrid battery itself. Rather, it has something to do with the hybrid battery charging system during high speed cruising. Beside this observation, MPG also dropped from 42-44 MPG pre-xmas last year to 33-35 MPG since Xmas last year. This drop in MPG was very noticeable and immediate as I was monitoring everything closely during the last 100 miles of the drive back home.

So I am just wondering what everyone is getting on the hybrid battery power indicator during freeway driving. I remember I used to get at least 7-8 bars (out of 10 I suppose) on the hybrid battery power indicator during both freeway and surface street driving. So having 2 bars only on freeway makes me suspect there is still something wrong with my car. But the dealer kept saying there is nothing wrong, even though I asked them why there are only 2 bars on the hybrid battery power indicator during freeway driving.

Anyone has some tip or hint of what is causing this? I appreciate the help. Is having 2 bars on the hybrid battery power indicator on freeway ​​​ normal for the ES300H, even though the car drives fine now? I attach a picture showing the 2 bars during the freeway driving. Thank you very much.

 

If driving more or less constant 70mph my battery stays near the top (within 2 bars). If I try to do some rapid acceleration bursts then the battery would be dropping.

You can check a few things:

1. Check that no brakes pads are binding - when driving on a freeway just coast to a shoulder and stop (do not use the brake pedal until very end). Feel all the brake rotors - they should be at just ambient air temperature.

2. Get Dr. Prius app with an OBD adapter and check for battery voltage & resistance uniformity and/or overall remaining capacity. https://priusapp.com/

3. Next time the same happens use this app and immediately store the error codes.

 

Hi NdYag,
Thank you for your suggestions. I appreciate it.