Diesel High Idle - Hot Days

[crspangenberg]

Hello all, after doing some digging I haven't been able to find a post or topic to answer this question.

 

I know that there is an elevated idle toggle in the infotainment system, which I have turned off. 

 

But is it typical for a 2022 GMC Sierra AT4 Duramax to idle around 1,000RPM during a "cold start" on a a hot day? Talking 95+?

 

This is my first diesel and I wasn't sure if it did this because it is trying to move more air through the condenser, or if this is atypical. The truck wasn't in Regen as it performed one less then 200 miles ago (my driving is predominantly highway).

 

Thanks!

 

P.S. I know that in the manual is says that during rainy days, your headlights will automatically come on with the wipers, are you seeing an indication on your dash showing the headlights are on? I asked the dealer and didn't get an answer.

[nards444]

13 hours ago, crspangenberg said:

Hello all, after doing some digging I haven't been able to find a post or topic to answer this question.

 

I know that there is an elevated idle toggle in the infotainment system, which I have turned off. 

 

But is it typical for a 2022 GMC Sierra AT4 Duramax to idle around 1,000RPM during a "cold start" on a a hot day? Talking 95+?

 

This is my first diesel and I wasn't sure if it did this because it is trying to move more air through the condenser, or if this is atypical. The truck wasn't in Regen as it performed one less then 200 miles ago (my driving is predominantly highway).

 

Thanks!

 

P.S. I know that in the manual is says that during rainy days, your headlights will automatically come on with the wipers, are you seeing an indication on your dash showing the headlights are on? I asked the dealer and didn't get an answer.

 

I have a 21 so same deal.  Guess I really havent let it sit running while its hot out for cold starts.  I suppose between moving coolant and the AC function it could kick on

[Michael621]

15 hours ago, crspangenberg said:

Hello all, after doing some digging I haven't been able to find a post or topic to answer this question.

 

I know that there is an elevated idle toggle in the infotainment system, which I have turned off. 

 

But is it typical for a 2022 GMC Sierra AT4 Duramax to idle around 1,000RPM during a "cold start" on a a hot day? Talking 95+?

 

This is my first diesel and I wasn't sure if it did this because it is trying to move more air through the condenser, or if this is atypical. The truck wasn't in Regen as it performed one less then 200 miles ago (my driving is predominantly highway).

 

Thanks!

 

P.S. I know that in the manual is says that during rainy days, your headlights will automatically come on with the wipers, are you seeing an indication on your dash showing the headlights are on? I asked the dealer and didn't get an answer.

My truck does the high idle for the first few minutes or so. There is a green head light icon that lights up, although if it is daylight out, I've noticed the lights do not turn on immediately with the wipers on. There is a delay of some sort.

[redwngr]

Elevated Idle in the infotainment section will only activate in cold weather. 

It will shut itself off when ambient and/or coolant temps are above the programmed in values.

 

If your truck never sees freezing weather it will not do anything. Ever.

 

The ecm and bcm have are many reasons why it can and will increase idle speed, and several amounts of idle boost that they use.

They are different from the idle boost during regen when stopped in traffic.

They are also different from the rpm level used by the 'elevated idle'
 

Most are related to electrical draw and charging system.