Engine on in `PARK` with foot on accelerator

brownne · 11-04-2005, 02:27 PM

Has anyone a rationale for this:

I had my Prius in PARK at the lights when I decided to press the accelerator - far enough depressed the engine actually turns on. `Great` I thought - if I want to charge the batterty when I am static, I can just put my foot on the accelerator.

No so though! - when I looked at the energy flow screen, even with the engine on in this situation, the battery (NiMh) does not appear to benefit.

Does anyone know what is the point of the engine igniting when the car is in PARK and the accelerator is pressed ? Is it charging the auxilliary battery ??　Is it good for anything other than wasted fuel??

ps. Please no comments to the effect that I should not press the accelerator when I am in PARK - my point is: Whats the point of being able to start the ICE with the accelerator (warming the CAT did cross my mind but why doesn`t the Engine Management System deal with this?)

mikepaul · 11-04-2005, 02:35 PM

Somewhere out there were 'speed charge' directions to refill the battery which were similar to what you did, but I thought it needed to be in D to make it work...

Frank Hudon · 11-04-2005, 02:38 PM

what you experienced is normal, and there is a very slight charge at about 1175RPM but to keep it there is really tricky, back off just a smidgen and it quits running and if you try to get to 1250RPM it quits charging. Also if the battery BSOC is high it won't charge at all. You can force charge the HV battery but I won't tell you how as it's a stupid thing to do as all you do is over heat MG1

Edited the 12 volt battery charges independent of the ICE running there is no conventional alternator on a Prius.

hdrygas · 11-04-2005, 10:48 PM

There is a previous thread on this and it makes no sense let the computer do it's work. Remember that what you see on the display is not full charge or no charge on the battery. It is the computers keeping the battery in an optimal range to maintain long battery life. The computers will not allow you to over or under charge the HV battery. See Frank's previous post.

nicksaadah · 11-05-2005, 01:32 AM

Hi all,

The last time I had my oil changed, they asked me to start my car up so they could check the oil pressure. I did, and seven seconds later (as expected), the ICE started, but soon turned off when they were not yet done doing their checks. They asked me if I could turn the engine back on, and I told them "actually - no I can't!"

So, I can think of one situation in which you might want to force the ICE to ignite, and thanks to you, I now know how to do it!

Thanks!
-Nicholas

Bill Merchant · 11-05-2005, 06:01 PM

Check the oil pressure??? How did they do that? Sounds bogus to me.

Frank Hudon · 11-05-2005, 06:20 PM

to check for oil leaks after an oil change just put the car in "B"

8AA · 11-05-2005, 09:13 PM

They weren't really checking the oil pressure, but needed the ICE to run so that the lubrication system could pressurize. If the oil filter is not seated properly, it will leak when the ICE is running. They were only checking to make sure that the filter was properly installed.

Even when the ICE is warm, it should run long enough for them to check, but if not, you can press the accelerator pedal down about half-way; just be sure the car is in PARK.

brownne · 11-08-2005, 04:27 PM

Quote:

Originally posted by Frank Hudon@Nov 4 2005, 07:38 PM
what you experienced is normal, and there is a very slight charge at about 1175RPM but to keep it there is really tricky, back off just a smidgen and it quits running and if you try to get to 1250RPM it quits charging. Also if the battery BSOC is high it won't charge at all. You can force charge the HV battery but I won't tell you how as it's a stupid thing to do as all you do is over heat MG1

Edited the 12 volt battery charges independent of the ICE running there is no conventional alternator on a Prius.

[snapback]150649[/snapback]

Thanks for all the replys. With regard to above, how do you know the engine rpm ? I didn`t think there was a rev counter on the Prius ??

Also, to force charge to HV batteries- could you just not find a big hill and let it coast down (in Drive) ? I`ve had it fully charged (on the indication at least) this way and it doesn`t seem to then stop charging - the car is still restrained by the generators (and not the engine) so the gravitational energy is going somewhere.

Thanks anyway - I`m still in the shade (not quite the dark) though as to why Toyota feel the need to let you start the engine like this. The comment about engine lubrication (or any other maintenance / test reason you need the engine on) seems to me to be the most likely reason.

Thanks again.

Frank Hudon · 11-08-2005, 05:23 PM

on my Classic Prius I have a MiniScanner that provides most of the data that I quote, rpm, engine temps, HV battery voltage and charge amps and discharge amps, 57 items in all that the car will not display.
On the wifes 2k4 Prius I have installed the CAN-view system and get rpm, HV battery voltage, charge and discharge, engine temp etc.
as a mechanic I've always thought the lack of instrumentation was the Prius biggest fault. Not that MG1 temp is really usefull in daily transport but just to know that if I'm towing my trailer and want to keep an eye on the MG temps I can do it.

11-04-2005, 02:38 PM	#3
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	what you experienced is normal, and there is a very slight charge at about 1175RPM but to keep it there is really tricky, back off just a smidgen and it quits running and if you try to get to 1250RPM it quits charging. Also if the battery BSOC is high it won't charge at all. You can force charge the HV battery but I won't tell you how as it's a stupid thing to do as all you do is over heat MG1 Edited the 12 volt battery charges independent of the ICE running there is no conventional alternator on a Prius. __________________ You can quote me on this, People who drive vehicles that idle at a traffic light, are idiots. mine 2k3 avg. 5.36 for 46,915Km Best tank 4.4L per 100K 64.2 Imperial 53.4 U.S. gallon, MiniScanner, SilverStars, block heater, winter lips, in as of Oct 15, out on April 25. In again on Sept. 21st. her's 2k4 "B" avg. 6.01 for 42,317 Km Best tank 4.02L per 100K, CAN-view with OBD11 module and flashloader, SilverStars, 06 Chrome grill bar, Michelin HydroEdge, upper and lower grill blocker,upper out as of April 7, lower out on April 28. In again on Sept 21st.

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11-04-2005, 02:27 PM	#1
brownne Join Date: Sep 2005 Location: West Yorkshire, UK Posts: 18 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Has anyone a rationale for this: I had my Prius in PARK at the lights when I decided to press the accelerator - far enough depressed the engine actually turns on. `Great` I thought - if I want to charge the batterty when I am static, I can just put my foot on the accelerator. No so though! - when I looked at the energy flow screen, even with the engine on in this situation, the battery (NiMh) does not appear to benefit. Does anyone know what is the point of the engine igniting when the car is in PARK and the accelerator is pressed ? Is it charging the auxilliary battery ??　Is it good for anything other than wasted fuel?? ps. Please no comments to the effect that I should not press the accelerator when I am in PARK - my point is: Whats the point of being able to start the ICE with the accelerator (warming the CAT did cross my mind but why doesn`t the Engine Management System deal with this?)

11-04-2005, 02:35 PM	#2
mikepaul Senior Member Join Date: Dec 2003 Location: Columbia, SC Posts: 1,742 My Car: 2004 Prius Model: Package: #9 Thanks: 1 Thanked 2 Times in 2 Posts Friends: 0	Somewhere out there were 'speed charge' directions to refill the battery which were similar to what you did, but I thought it needed to be in D to make it work...

11-04-2005, 10:48 PM	#4
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	There is a previous thread on this and it makes no sense let the computer do it's work. Remember that what you see on the display is not full charge or no charge on the battery. It is the computers keeping the battery in an optimal range to maintain long battery life. The computers will not allow you to over or under charge the HV battery. See Frank's previous post.

11-05-2005, 01:32 AM	#5
nicksaadah Join Date: Oct 2005 Posts: 40 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Hi all, The last time I had my oil changed, they asked me to start my car up so they could check the oil pressure. I did, and seven seconds later (as expected), the ICE started, but soon turned off when they were not yet done doing their checks. They asked me if I could turn the engine back on, and I told them "actually - no I can't!" So, I can think of one situation in which you might want to force the ICE to ignite, and thanks to you, I now know how to do it! Thanks! -Nicholas

11-05-2005, 06:01 PM	#6
Bill Merchant absit invidia Join Date: May 2005 Location: USA \| Oregon \| Portland area \| 97004 \| Posts: 4,100 My Car: 2007 Prius Model: Package: #5 Thanks: 18 Thanked 10 Times in 8 Posts Friends: 60	Check the oil pressure??? How did they do that? Sounds bogus to me.

11-05-2005, 06:20 PM	#7
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	to check for oil leaks after an oil change just put the car in "B"

11-05-2005, 09:13 PM	#8
8AA Senior Member Join Date: Feb 2004 Location: Maryland Posts: 492 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	They weren't really checking the oil pressure, but needed the ICE to run so that the lubrication system could pressurize. If the oil filter is not seated properly, it will leak when the ICE is running. They were only checking to make sure that the filter was properly installed. Even when the ICE is warm, it should run long enough for them to check, but if not, you can press the accelerator pedal down about half-way; just be sure the car is in PARK.

11-08-2005, 05:23 PM	#10
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	on my Classic Prius I have a MiniScanner that provides most of the data that I quote, rpm, engine temps, HV battery voltage and charge amps and discharge amps, 57 items in all that the car will not display. On the wifes 2k4 Prius I have installed the CAN-view system and get rpm, HV battery voltage, charge and discharge, engine temp etc. as a mechanic I've always thought the lack of instrumentation was the Prius biggest fault. Not that MG1 temp is really usefull in daily transport but just to know that if I'm towing my trailer and want to keep an eye on the MG temps I can do it.