900 Owners

[98 Z71 SLT]

According to the owner's manual for my 2008 Sierra, some trucks are equipped with a fast idle system. The manual doesn't specify gas or diesel engines, so can we assume we have a fast-idle system, and most of us don't even know/use it??

 

You must have cruise control buttons on the steering wheel to even have this option.

 

http://service.gm.com/servlets/BlobShtml?S...spsdsubkey=6717

 

Opinions?

[Ranger]

Never heard of it...It's either the tow/haul mode (unlikely, as my tow/haul doesn't increase the idle speed) or an automatic process. I have noticed my idle go up to 800-900 rpms depending on engine temps and other conditions.

[99silverado1500]

My dads 08 Duramax, and 07 LBZ Duramax, both have fast idle, but as far as I know the gas engines do not. His is in the DIC.

[98 Z71 SLT]

My dads 08 Duramax, and 07 LBZ Duramax, both have fast idle, but as far as I know the gas engines do not. His is in the DIC.

 

 

OK. Like I stated, the text does not specify gas / diesel powerplants.

[d3athsong]

Fast idle package would be on diesels. Never heard of a fast idle package on a gas nor a reason why there would be one.

[Bostonsfavson]

Zee link, zee is...FORBIDDEN! At least for me

[99silverado1500]

Yep, i looked it up, just on the Duramax.

[98 Z71 SLT]

Why in the world would GM stick this info in a regular owner's manual??

 

SHOULD BE in the Diesel Supplement Manual (which is supplied with every diesel truck purchase)

[99silverado1500]

Probably just something for Duramax owners that do not read their supplement or something, or just a idiot warning, you never know these days.

[Raymond Lowe]

It's a pretty common option on HD pickup trucks used in commercial applications. The fast-idle raises engine speed to power a PTO driven hydraulic pump more efficiently. Uses include tow trucks, trucks with booms, lifts, dumps, etc.

[SinisterSS]

Before winter I programmed my own high idle with EFILive. The rpm starts out low when the engine is cold and as it warms up, the idle speed gradually increases up to 2000 rpm at about 180 degrees and then the final 10 degrees of warm up, drops back down to normal idle.

[d3athsong]

2000rpm at an idle seems really high.

 

So is this EFIlive one of the programs used for tuning?

[gave20]

You have to be careful with the high idle, extremely cold temperatures have been known to cook the Allison when using the setting.

[rdmforestry]

You should check your dealer for warranty updates if you are going to use your fast idle. For Canadian models anyway I believe 06 and newer there is a programming issue in the TCM that may cause your tranny to overheat and fail in cold weather...something to do with the torque converter...in any case following the recent cold weather there have been many tranny failures in Northern Alberta. I just took mine in today...the invoice reads

 

"program V1749-REPROGRAM TCM AS PER CAMPAIGN #07293"

 

I wouldn't use your fast idle until you get the update. My dealer knew nothing about it...when they checked their compter it was there...you think they would be more on top of things with a major issue like that.

 

 

 

 

You have to be careful with the high idle, extremely cold temperatures have been known to cook the Allison when using the setting.