Has anybody noticed when stopped at a light with the heat on when temperatures are about 45 degrees or lower, with the engine shut off it starts back up afer about 1 minute. I assume that the car can not produce heat electronically and has to start up to circulate hot water through the coils. Let me know if anybody else has experienced this.

I've noticed if I switch from "ECO" mode, or back into "ECO" mode with the heat on, I can get the ICE to shut down when stopped. I don't know how/why this happens. Also, the ICE seems to come on with the heater on even if the engine has warmed up to the normal operating temperature.

I knew the air conditioner would affect my FE, but I never thought the same would be true of the heater.

I have not noticed the engine coming on at a light with the air on at a stop, just the heat. You may be right, I may not have been fully warmed up, I will have to observe it. I have noticed the eco mode turning it's self off when I have not even filled the tank (hitting in error).

Josh,

I didn't mean to imply that the engine was coming on while at a stop with the A/C on, only that I knew FE would suffer because of the extra strain the A/C puts on the engine.

If the engine has JUST hit baseline warmth and you stop, the engine will come on because the temp will almost immediately drop below the trigger point. If it happens after you have been driving for a while, that might be something else. Also, from what I understand, the engine can also come on to power up various systems as needed, I beleive brakes fall in that category.

I've found that if the car is still warming up and the engine stays on at a light I can just hit the off button for the climate control and the engine will immediately turns off. (I turn it back on when the engine comes on after leaving the light.)

Actually the AC compressor does not put a strain on the engine directly as it does in most cars. There's no direct connection (belt) for the AC Compressor on a TCH. It is driven (always) via it's own electric motor. Hence the reason a TCH can run it's AC while in EV mode.

Regards - Randy




If there's one thing I've learned in online forums its this:
Never argue with an idiot, they'll drag you down to their level and beat you with experience!

Josh, I notice you're in NJ. I'm not sure how familiar you are with this, but just in case ...

If you turn temp to MAX heat (or MAX cold -- not a problem for you ), the ECO mode will be automatically disengaged. (The same is true if you turn on the front defroster.)

This may be what is causing the ECO to shut off.

John


2007 TCH -- Desert Sand, Bisque -- Original Equip: Leather Seats; NAV; Moonroof; Heated Seats; Body Side Moulding; Carpet/Trunk Mat set; Front License Plate Mounting Bracket
Completed Mods: Moved the side "HYBRID" emblem/badge to trunk lid; Mud Guards (Colored); Back-up Sensors; Door sill protector; ScanGauge II; Front Bra (Clear LLumar); Window Tinting (40 % Charcoal LLumar); Rear Deck Lid Spoiler
Mods in progress: None
Future mods: Rear bumper appliqué, Sliding Center Armrest

The heat in your car is pulled out of the engine. The heater core to be exact. Your antifreeze has to be up to temp for your heater to work. Your antifreeze is heated by the engine. When you use the heater you are pulling heat out of the antifreeze thus cooling it off. Once it gets too cool the ICE starts up to heat the antifreeze back up.
For more information http://auto.howstuffworks.com/cooling-system10.htm

If you ever have a car overheating ALWAYS turn the heat and fan on full blast. It will cool the antifreeze which inturn will cool the engine.

Personally I am shocked the the TCH does not have an electric heater. At some of the long lights here in town my engine has come on and off a few times with the heat set about 79 - 81.

[quote=FL07THC;100195]The heat in your car is pulled out of the engine. The heater core to be exact. Your antifreeze has to be up to temp for your heater to work.

There is also a supplementary electric heater it's called a PTC heater, here is Toyota's description of it:-