ICE comes on anyway

DUDE!! That totally sucks the big linguini!! I wonder if it's a software problem that could be repaired with a reset/reboot approach? The main difficulty will be to find someone qualified to troubleshoot this problem who gives a damn!! Corporate call Time!!
Need to find another Prime like yours, in your area, who'll go on a little tour with you!! I haven't followed every detail of your saga, but is the problem only occurring in very cold weather, near sea level? A road trip to Michigan crossed my mind, but you're not exactly 2 blocks away!!

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Have you considered not driving on 14 mile road? Problem solved.

Really weird all the way around.

 

Ah, I hadn't been following closely enough to read that!! So what do we do now, get a pronouncement from Corporate??!! Come on Toyota, help us out here!! Our friend has a mystery that deserves an answer/solution!!

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We're going to need more technical details, a video with audio of this problem. In particular, the display showing SOC, power, and speed:

• trip meter - gives distance and MPG
• speed
• mode (green blob, needs to be sharper)
• temperature
• SOC %
• requested power

With the audio, we should be able to tell when the engine comes on and work the problem backwards. If you can call out where this happens, we can use Google Earth to look at the grade and NOAA for weather conditions.

Bob Wilson

 

Here's more data to ponder...

 

I use an iPhone to take the video (updated in edit) of a benchmark. If you have a fixture to hold the cell phone to the dash, say using 'blue' masking tape (peals clean for painting) and/or consider fabricating something using cardboard and tape. Once started, leave it running; start the car, and; replicate the benchmark. Do not worry if there is an 'opps'. Just lessons learned; fix, and; replicate the next day.

I am curious about the double "EV" green icon, @john1701a in your video. I only see a single one on my Prius Prime Plus: ICE comes on anyway | Page 26 | PriusChat

Bob Wilson

 

Curious. I use "Normal" mode since I found ECO mode too lethargic and POWER too fidgety. Notice how the video lets us see obscure aspects we've grown used to but different from what others might not use.

Bob Wilson

 

Try Drive Mode button to the right of the shifter.

 

Temperature here 18 degrees and lower at times, have had the ICE start and run for a short time in EV mode on two occasions. Once briefly under hard acceleration over 60mph. Except for those two times EV mode has been all electric at speeds up to 65mph. Experimenting a bit... By cranking up the temp, seat and steering wheel heater have been able to get the climate load near 50%. With snow/ice on streets and cold have seen miles/kilowatt hour drop as low as just over 2, down from 5 in more temperate weather. Indicated range is down from low 30s to 25.3 this morning but with climate set at a more moderate 67 degrees and using seat and steering wheel heater actual range is looking more like 20 miles. Conditions where my gas powered SUV gets around 8 mpg - to keep things in perspective. Can't wait to see how it handles temperatures at 0 and below. This Prime is such a fun and interesting car and it looks great too!

 

Perhaps a little redundant but this is how I analyzed engine warm-up underway:

There is an interesting frame-by-frame result using "." and "," to forward and reverse:

• frame - observations
• 1 - EV icon lit and the auto shape by power curve is green with EV
• 2 to 6 - EV icon goes bank and auto shape changes slightly smaller with green EV and power bar goes away (could be undulation of road)
• 7 to 8 - auto shape remains an outline
• 9 to + - auto shape outline joined by power bar (could be undulation of road)

This suggests there are some rapid changes, faster than an unaided eye can see, that can be documented by the video.

So I used "." and "," to forward and reverse frame-by-frame. Every time the 1/10th mile indication changed, I recorded the metric in a spreadsheet:

• During the first 9-18 seconds, the engine spins up to get oil pressure up without a mechanical load. Then gas injection starts.
• The engine starts and runs with a constant fuel consumption for about 60 seconds, 1 minute.
• Once warmed up, the engine fuel consumption increases to sustain the speed and replace the missing charge lost while the engine warmed up.
• Around 200 seconds, the traction battery SOC was high enough that the regular hybrid mode that cycles the engine can start.

In my test, the switch was operated manually. But now I am wondering if the OP may be suffering from a defective switch or loose connector that might be sensitive to something else and spoofing a button push. Some of the worst intermittent problems have been traced to loose/defective connectors and or switches. They won't fail unless some specific conditions are met of which one is "DO NOT FAIL WHEN SERVICE TECHNICIAN IS WATCHING."

Bob Wilson

 

Reading all these extremely-cold-weather posts, I get a little insight on how truly spoiled I am to be living in Socal. I admire you folks who can deal with what those temperatures entail!! BRRRRRR!!

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Ah, the "nut behind the wheel" hypothesis. So far, no one has replicated your symptoms other than when I pushed the button to put the car in hybrid vehicle (HV) mode which I recorded on a cell phone video.

I would like to see a similar video in your car to find out if it is identical or different from manually pushing the button. Then we can document that it happens without pushing the button ... on video.

We use video recording to look at what the operator is doing just before or during the event. There may be some previously, unknown sequence that can trigger the event. But first, let's eliminate the obvious, the button push.

Bob Wilson