Turning Ignition Key... While the Engine is Running (1 Viewer)

[Manhattan]

Ever done it? I can't speak to any year other than a 2006 (okay, and 2007), but in a 2006, this does not produce the horrible grinding sound of the starter attempting to engage the spinning flywheel. Turning the key while the engine is running essentially just resets the Nav, stereo, display, etc. It does not interrupt anything associated with driving. I use this "feature" occasionally to reset the GROM if it's glitching.

I wish I could remember when I first did this... and why I knew it would not do what we'd expect it to do.

But the big question(s): Why does this feature exist? Or, did the Toyota engineers just put an idiot override in place, e.g. "if engine running then..." in the ECU firmware?

 

[jLB]

I’d assume that it’s part of the “crank and hold” system that my 06 LX has, (where I don’t have to hold the key in the start position) but 99 LX and 00 LC do not have.

If I remember correctly my 03 GX470 & 04 T4R also had the “crank and hold”, so I’d expect that it was added to the LC/LX ~2003.

 

[Ayune]

In the START position the ignition switch disconnects accessories/lights/etc. so all power can be diverted to the starter and stuff related to running the engine.

Yours doesn't grind because, indeed, the auto "crank-n-hold" system senses the engine is already running, so no need to engage the starter pinion solenoid.

Older years will trigger the starter pinion solenoid and grind, with the same electrical... benefits?

 

[GatorBait1551]

Ever done it? I can't speak to any year other than a 2006 (okay, and 2007), but in a 2006, this does not produce the horrible grinding sound of the starter attempting to engage the spinning flywheel. Turning the key while the engine is running essentially just resets the Nav, stereo, display, etc. It does not interrupt anything associated with driving. I use this "feature" occasionally to reset the GROM if it's glitching.

I wish I could remember when I first did this... and why I knew it would not do what we'd expect it to do.

But the big question(s): Why does this feature exist? Or, did the Toyota engineers just put an idiot override in place, e.g. "if engine running then..." in the ECU firmware?

Nice, I'll have to remember this when my Grom is acting up. My 04 also has the crank and hold