ICE comes on anyway

really? you have to use the keywords inside the quote.

 

navigation map version

 

are you searching all forums? it's the first hit when i search.

 

if you need more help, the thread is in the prime audio forum.

 

Immediately.

 

About 3/4.

 

It is entirely possible there is a temperature range that the symptom occurs. Living in Dixie, it hard to test sub-freezing temperatures and earlier today, I could not trigger it at 50F indicated.

I parked the car at 75% SOC and temperatures are approaching freezing. I'll try to replicate it. It did not start engine.

Putting full charge on and will try again.

Bob Wilson

 

That would do it in cold temps. You're drawing over 100 A from the battery and, from my experience, under similar conditions, the computer takes over and says: "Redirect the energy to the engine."

 

It is important to video record every test because the failures teach us too:

• Delay between cruise control ON and SET - did not Engine-ON
  • cruise control ON while stopped
  • cruise control SET while ~44 mph
  • 27 seconds between ON and SET
  • 36F (2 C)
• No delay - Engine-ON occurred
  • Due to poor contrast, the video is unusable for metrics.
  • cruise control ON and SET while ~44 mph
  • 36F (2 C)

I’ve analyzed the video. Temp 34-38F (2-3C), 100% SOC at start.

Bob Wilson

 

My ICE starts up some mornings while driving in EV mode too. Have the parameters that cause it been clarified ? I apologize if the answer is already in this thread and would appreciate a post #.

FWIW, I drive a hilly road in temps around 20F after a long soak, and the SOC is 10-20% when I start my drive. Since the ICE operation is automatic I'm reasonably sure I am triggering a condition. The display shows I am in EV mode, but the energy consumption bar is blank and my EV icon disappears.

I'm most inclined to think that the trigger is a battery current draw above some threshold for the conditions at the time. Cold batteries push much less current, and I think that the trigger occurs when I step on the go pedal. If I am right, @priuscatprimeguy triggers the car behavior by acceleration, not the car speed per se.

 

It was obvious you were doing something outside of the "predictable" use cases. We've encountered that a number of times over the years, where some critical bit of information was unknowingly omitted.

My all-time favorite was from a Prius owner who complained about the car rolling forward unexpectedly. It took weeks for us to figure out that this owner, who had been driving for over 50 years, had never been behind the wheel of a vehicle with an automatic transmission. It never dawned on any of us that natural forward-creep behavior was something he hadn't ever encountered over all those decades. That doesn't exist with manual transmissions. It sure was a learning experience for us.

Another big "problem" of the past was the lock-up at start-up. Some owners were reporting the dashboard lighting up like a Christmas tree and the Prius never getting to Ready mode. It would lock the transmission, not allowing you to shift the selector. Eventually, they'd figure out how to force the system off. The next time they'd try, it would work every time. Our debugging efforts took forever. Turns out, when we asked if they were pressing the brake first (as instructed), before pushing the Start button, they actually weren't doing that. Not being attentive enough to notice the timing was key. If you were slightly ahead with the button... only a fraction of a second... the self-inflicted problem arose.

One other story was the "brake pause" issue. When you've been driving for that many miles and there's a claim of the system having a dangerous flaw, yet never experienced it yourself... despite trying to replicate the claimed situation... it makes you wonder. After weeks of posts, we finally got our answer. You had to be braking aggressively, then smack into a substantial road-hazard, at the peak of deceleration. I rarely ever brake that hard. Hitting a pot-hole or train-track that that exact right moment was quite a bit less likely. Finally putting those pieces of the puzzle together brought a much better understanding. Toyota did indeed tweak the parameters of the brakes to better deal with that rare situation too.

Will they do anything for those choosing to use cruise-control in low-speed driving with cold battery? Most likely not. The "predicable" use of the car is to plug it in overnight. That's an expectation for a plug-in vehicle, especially since it has a battery-warmer. Not doing that defeats the overall purpose of getting owners to equip their overnight parking location with a permanent charging option. That's how they'll get you to upgrade your current plug-in with one offering a larger capacity in the future. Doing less means getting less.

It was yet another interesting learning experience for all of us.

 

I concur and want to make it clear there is a second, independent, engine-ON condition, 14F (-10C). There is evidence that some colder climate owners have not been able to replicate the symptom and preconditioning and/or sitting in READY for 5 minutes apparently inhibits the problem.

I'm still investigating to fine tune the criteria. For example, 23 mph is the lowest cruise control speed without dynamic control and 28 mph with dynamic control. What is the lowest speed that cruise control can be turned ON, not SET, and defeat the symptom?

In Dixie, we have limited access to cold temperatures but I'm patient. I've also seen that I can run multiple tests in a day if I can get the car fully charged.

Bob Wilson