Last post on Dec 18, 2012 at 8:32 PM
You are in the Toyota Highlander Hybrid
What is this discussion about?
Toyota Highlander Hybrid, Fuel Efficiency (MPG), SUV
#443 of 447 Re: 2006 HH Lowering Gas Mileage resolved (I think) [newski3]
Feb 15, 2011 (2:13 pm)
I previously posted the information that if the "normal" battery on the '06 HyHi was disconnected for any reason, your hybrid computer would be reset to default upon reconnecting the battery. Followup to this, I have learned that there is a Toyota Service Bulletin (TSB) (EG026-05) warning that the Idle Speed Control (ISC) might need to be reset if the "normal" battery is disconnected. So, disconnecting the battery seems to reset the computer but it will most likely cause the ISC to need resetting. Symptoms will be:
1. Reduced gas mileage.
2. Engine seems to run longer when slowing down or at a stop.
3. Engine noise at low or idle rpm. I had all three symptoms after disconnecting/reconnecting my battery. One owner reported that he was charged about $80 for Toyota service to reset the ISC. However, someone else posted a do-it-yourself method. I tried the latter and it seems to work. I repeat it here in case you are experiencing one or all three:
"1. Drive the car for at least 15 minutes under engine load to warm the engine and coolant to normal operating temperature.
2. Park the car, shift into P, turn off all electrical (a/c, radio, lights, etc.).
3. Turn the car off, then back on.
4. Set your hybrid status screen to show the battery charge level.
5. Hold the brake pedal down (I used my left foot), shift to D, continue to hold the brake pedal down all the way, then press the gas pedal down until the engine comes on and begins charging the hybrid battery. The car will not move or attempt to move, so don't worry - but the brake pedal must be kept firmly down!
6. Repeat the above for 30-40 second intervals until the hybrid battery is fully charged - the battery status will be green and full and you'll notice the engine stops revving when you press the gas pedal down.
7. Shift back into P, turn the car off for 5 seconds, then back on and press the gas pedal enough to kick the engine on.
8. Let the engine continue to run on its own (no pedals) until it cycles and then shuts itself off.
9. Either drive off at this point (you can turn A/C, radio, etc, back on), or shut down." --unquote--
As I said, this procedure seemed to have worked for me. Also, I wasn't sure what the "Repeat the above.." in step 6 meant so I assumed it meant to cycle the shifter back to P after taking foot off of gas, and then back to D while of course you keep the brake depressed, and then reapplying the gas.
Again, this seemed to work for me.
#444 of 447 recent decrease in mpg (to 19pmg) on econ mode
Jul 25, 2011 (5:41 am)
Have a 2008 highlander hybrid. bought it 5 months ago with 32k miles. was getting about 25mpg. Then about a month into it, around the same time the soon to be recalled issue of the sensor started going off (http://www.autorecalls.us/recall_search.php?hdRecallMake=Toyota%7C79&hdRecallMo- del=Highlander+Hybrid%7C1476&ddRecallMake=Toyota%7C79&ddRecallModel=Highlander+H- ybrid%7C1476&x=25&y=10) , and the dealer reset the warning, the MPG plummeted to around 19mg! although isn't terrable, it is terrible for a hybrid.
I visually checked the battery and , and the light on the battery itself shows it's good.
any ideas why this would be happening?
Frankly, for this kind of gas millage, i would have bought a non-hybrid!
thank you for your help,
#445 of 447 Re: recent decrease in mpg (to 19pmg) on econ mode [lam8]
Aug 08, 2011 (8:52 am)
I too have a 2008 HH that I'm having some mileage issues with. City mpg ranges from 28+ down to the low 20s. The issue seems to be with the regenerative braking system. When mileage is good, the charging needle is pegging out to the max when I brake and I'm recovering a lot of energy. When mileage is poor, the needle barely moves. However when I see this and shift into B, the needle drops down more into the charging zone.
This tells me that I have a problem associated with brake pedal position sensing. The dealer says that if there is a faulty sensor then the check engine light should come on, which it has not. They offered to run their diagnostics. If they find a bad sensor, it will be covered under warranty; if they don't find anything, then I pay up to $125 for their time.
Is this anything like what you are seeing? Does anyone else have this issue?
#446 of 447 Re: recent decrease in mpg (to 19pmg) on econ mode [markg14]
Aug 09, 2011 (12:09 pm)
The check engine light is only for emissions related problems which I would not think your problem falls under.
#447 of 447 Re: 2006 HH Lowering Gas Mileage resolved (I think) [newski3]
Dec 18, 2012 (8:32 pm)
Brand new 2012 HiHy - gets 13.5 l / 100 km instead of the advertised 7.3. Dealer was no help.
Followed newski3 procedure to reset the ISC. The system is much improved.
Thank you very much.