1227747 ADSU bin HotRst questions

[damanx]

I am curious about the 5 HotRst parameters in the ADSU bin.

There are 5 settings:

Duration = 10 seconds
IAC Steps Added = 30
Shutdown for CTS restart = 111.0 C
Key on CTS for Hot Restart = 90.0 C
AFR Enrichment = 0.20

I am assuming that whatever conditions are met, the IAC 30 steps and AFR is applied for 10 seconds. What does the Shutdown parameter and Key on parameter do?

Also,

Let's say you go to the store. The engine temp is at operating temp when you get there, park and shut the engine off. You come out a few minutes later.

What occurs when you put the key in and turn the key to "on" for several seconds before starting and, is there anything different that occurs if you immediately put the key in and start?

I am curious as I occasionally experience a condition where the engine runs up to about 1700 rpm on a hot restart that last for what seems to be longer than 10 seconds.

[RobertISaar]

looks like the hot restart code that's used in other PCMs too...

key on is refering to startup coolant temp, if it's above that, it will continue checking the other requirements rather than immediately disable.

shutdown may be referring to the engine needing to be that high of a temp at time of shutdown for a flag to be enabled in the NVRAM, so when the next key-on sequence happens, if it's above the startup temp, hot restart is enabled.

[damanx]

I'm going to assume that, that particular flag will never be set in mine since the operating temp of my engine is between 195 F and 200 F on average.

[ony]

when you park the temp may go a little higher for a short time as the heat soaks from the metal to you coolent.