Just wondering! Sometimes when my energy screen on my TCH says the engine is off, the scangauge tells me different. The rpm on the scanguage will be at 925 to about 1200. The exact rpm doesn't matter here, but the fact that the scanguauge says the engine is running, even though the TCH display says it's off, as in no arrows from the engine. At the same time the mileage indicator to the left of the speedometer will be hovering at 60mpg while moving. But the same condition sometimes happens when I am not moving such as stopped at a red light. Then the mpg indicator will hover above 0 mpg but only for 7 seconds till the engine stops. You can always tell when the engine stops when this mpg indicator falls under the 60 mark. My question is if anyone has noticed the same condition and if so why this is like this? If the engine is in fact running, why isn't the display showing this and why are there no arrows going to the battery? Hope I described this correctly. Has anyone else noticed this condition or am I alone? Just trying to figure out how this car works. Thanks, Rick

 

There's no engine off indication on the TCH's (or 2nd gen Priuses) color touchscreen MFD. No arrows does NOT mean the ICE is off.

If I've been reading everything about the Prius right and how the power split device works along w/the MG1 and MG2 RPM limits, the ICE must also spin at speeds >42 mph. I believe the 42 mph threshold is the same on the TCH.

The NAH has an EV mode light that should indicate when the ICE is off. I haven't plugged my new ScanGauge into my mom's NAH to confirm though.

(I only had a loaner TCH for 1.5 days and it had nav so it had the color touchscreen LCD. I didn't have enough time to become familiar w/the black and white small LCD in the gauge cluster and how well it correlated w/the MFD.)

 

That could be it. I was assuming that if there were no arrows going from the ICE in the color touchscreen, the engine was off. I just don't understand that if the ICE is running, why it wouldn't be recharging the battery, whether moving or sitting still. You are correct that the ICE must spin over 42 mph. As for the small LCD in the gauge cluster, it doesn't contain any more extra info than the touchscreen except for the odometer, the two trip meters and the outside air temp. I'm just trying to find out as much about this car as I can. Thanks, Rick

 

On a side note, you might find the PDF at http://priuschat.com/forums/knowledg...rence-aid.html interesting.

I don't know how closely this follows the TCH. I would expect the IGN timing values to be way different since the engines are totally different.

 

I had a slight problem with my Scan Gauge II. I called Linear Logic, SC's main office in Mesa, Az. A tech told me how to make an adjustment on the fuel-cut page. That fixed my problem of the sluggish engine shut down reading on the scan gauge.

Linear Logic

888 433-5664

480 656-4089

 

Care to share what they had you do and how?

Thanks!

 

What does the Cutoff function do? (from Linear Logic)
Some vehicles will turn the fuel injectors off when coasting down. We sense this with the open/closed loop indicator and the throttle position. We have to know if the throttle is opened or closed but the minimum value for it is rarely 0. The Cutoff is the value the throttle has to be below in order to indicate a fuel cutoff and show 0 fuel flow.
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First you read your TPS (throttle position) at idle. (engine warm) Take the number 14? and add 2 to it. Set the fuel cut-off number to 16. This is per linear logic.

Some other forms say add 1 to the TPS for the cutoff number. The scan gauge II should come with the fuel cut-off default set to 24 for most vehicles.

The default is right for most vehicles, but it can be adjusted for different situations. If set to "0" it disables this method of fuel cutoff sensing.

 

I doubt changing the cutoff will have any effect on the RPM reading. Also, on the Prius, when ICE is at 0 RPM, I notice that IGN is at 5. I'd imagine the TCH also has similar behavior but a different value.

 

The fuel cut off from the sensor is so the rpm and other readouts go to zero or toyota default minimum when the engine is off.

 

I think what confused me was that when the MFD showed no arrows leaving the ICE, I assumed the ICE would be off. So naturally with me thinking the ICE was off, I'd also assume the rpm on the scangauge would be at 0. But sometimes the MFD shows no arrows coming from the ICE. At the same time, I can hear the ICE running and the rpm on the scangauge is somewhere between 900 and 1200. Usually I'm coasting or slowing down for a stop. Again everything with the TCH and the scanguage seem to be working ok. cwerdna said in a previous post "No arrows does not mean the ICE is off". I agree because I've seen this condition. So, if the ICE isn't off and in fact is running with no arrows leaving the ICE, you are coasting or at a stop, and your battery is not fully charged, then what would be the reason for the ICE to be running? With these conditions wouldn't it make sense to be charging the battery? The same scenario with the ICE cold, produces an arrow charging the battery. Not a problem but I must be missing something. Rick