High Idle Enable

[sceptre]

hey guys, I posted this in electronics but didn't know if I would be better posting it in here so I hope I dont get crap for putting it in both places. I'm wondering if there is a way to enable high idle, on a 2011 duramax, with a remote start/alarm system? Is there an input on the ECM somewhere maybe?

[Diesail]

On the old trucks it was a pin on the ECM and you could wire your own switch. Since 2007.5 it is all software and there is no way to do it yourself. It has been hinted that it would be possible to have the dealer add it but so far nobody has had any success to my knowledge. So if you didn't order you are stuck.

 

Whad do you need it for anyway?

[jro909]

On the old trucks it was a pin on the ECM and you could wire your own switch. Since 2007.5 it is all software and there is no way to do it yourself. It has been hinted that it would be possible to have the dealer add it but so far nobody has had any success to my knowledge. So if you didn't order you are stuck.

 

Whad do you need it for anyway?

 

 

he lives in alberta canada, it gets quite cold there i think...if it were me i'd just plug the thing in and start it 15 minutes before i drive...modern diesels aren't like their grandfathers

[Bluedog]

High idle CAN be added by your dealer by requesting a new program from GM. I have the instructions that GM Upfitter sent me if you're really interested. A neighbor of mine has tried to get it done, but every dealer first gives him crap about it, and then wants to charge big money to do it.

 

I'm assuming you have turned on the elevated idle feature already. That works as well as the high idle does (except you can't set it for the engine speed you want) and it comes on automatically if it is cold enough to need it.

[sceptre]

On the old trucks it was a pin on the ECM and you could wire your own switch. Since 2007.5 it is all software and there is no way to do it yourself. It has been hinted that it would be possible to have the dealer add it but so far nobody has had any success to my knowledge. So if you didn't order you are stuck.

 

Whad do you need it for anyway?

 

 

he lives in alberta canada, it gets quite cold there i think...if it were me i'd just plug the thing in and start it 15 minutes before i drive...modern diesels aren't like their grandfathers

 

 

Its already -30C...will probably drop another 15degrees or so by january. The factory idle enable works relatively well but just takes a while to heat up on cold mornings. Also, my truck is damn near always plugged in once it drops below -15 because you never know how cold it will get here overnight sometimes

[8.1HD/ALLISON]

I think this is what you might be looking for. Let me know if it works.

 

Manual High Idle System Description

 

The diesel engine has a high idle system to improve the warm-up time of the engine in cold weather conditions. This system allows the engine control module (ECM) to increase the idle speed above the normal calibrated value. The ECM increases the idle speed using the following adjustments:

 

 

• The fuel injection timing is changed

 

 

• The fuel injection quantity is changed

 

 

• The turbocharger vane position is commanded closed--The vane position will be farther closed than any other normal operating condition.

 

The instrument panel will indicate the high idle system is active one of two ways:

 

 

 

• The driver information center (DIC) will indicate an active high idle.

• The manual high idle feature comes enabled from the factory. The Elevated Idle function in the scan tool will disable or enable this feature. If the engine does not increase to the calibrated high idle speed after the procedure is performed, use the scan tool to verify the Elevated Idle speed feature is enabled.

 

 

• The driver information center (DIC) will indicate an active high idle.

 

 

• The manual high idle feature comes enabled from the factory. The Elevated Idle function in the scan tool will disable or enable this feature. If the engine does not increase to the calibrated high idle speed after the procedure is performed, use the scan tool to verify the Elevated Idle speed feature is enabled.

 

 

Manual High Idle Speed Enable and Disable

To enable or disable the manual high idle system perform the following procedure:

 

 

<LI type=1>Turn the ignition ON, with the engine OFF. <LI type=1>Depress the accelerator pedal to the floor and hold down. <LI type=1>While the accelerator pedal is depressed, depress the brake pedal 3 times in less than 8 seconds. <LI type=1>Release the accelerator pedal.

1. Start the engine.
   

When the procedure is followed the engine idle speed will slowly increased to the calibrated high idle speed of 1,200 RPM.

 

The idle speed will return to normal if any of the following conditions occur:

 

 

• There is brake, clutch, or throttle input from the driver.

 

 

• The

automatic transmission is shifted out of Park or Neutral.

 

 

• The air temperature is more than 7°C (45°F).

 

 

• The engine coolant temperature (ECT) is more than 68°C (154°F).

 

 

• The

vehicle speed exceeds 0 km/h (0 mph).

 

The high idle system will reactivate automatically when the following conditions occur:

 

• The engine has been idling for more than 30 seconds.

 

 

• The transmission is placed in Park or Neutral.

 

 

• The vehicle speed is 0 km/h (0 mph).

 

 

• The ambient air temperature is less than 3°C (37°F).

 

 

• The ECT is less than 68°C (154°F).

 

 

• The brake, clutch and throttle pedals are not depressed

 

 

 

 

 

[Bluedog]

I think this is what you might be looking for. Let me know if it works.

 

Manual High Idle System Description

 

The diesel engine has a high idle system to improve the warm-up time of the engine in cold weather conditions.

 

The idle speed will return to normal if any of the following conditions occur:

 

 

• There is brake, clutch, or throttle input from the driver.

 

 

• The

automatic transmission is shifted out of Park or Neutral.

 

 

• The air temperature is more than 7°C (45°F).

 

 

• The engine coolant temperature (ECT) is more than 68°C (154°F).

 

 

• The

vehicle speed exceeds 0 km/h (0 mph).

 

 

 

You described the standard elevated idle feature that comes with all the Duramax trucks. The OP was referring to an optional feature RPO UF3 called "High Idle Switch" - the difference being that the higher idle will be available all the time, not just when the coolant is cold. With the standard elevated idle, as soon as the coolant reaches 154 degrees as noted above, the idle will return to normal. In a cold environment, this won't keep the engine warm as once it kicks off, the idle goes down, and the engine cools back off. It does not automatically pop the idle back up once the engine cools below the set point.

 

By using the optional feature, the higher idle speed will be maintained, and the engine will stay warmer.

 

As noted above, this option supposedly can be added by the dealer, but I have seen no one post in any forum that they actually had it done...

[8.1HD/ALLISON]

I see. Haven't had much experience with diesels. Just going off the book. Thats good to know, didn't know they had that option. If its an available program from GM, shouldn't take much to have the ECM reflashed. We don't get that kind of cold here in Indiana.

[BlackSilver]

hey guys, I posted this in electronics but didn't know if I would be better posting it in here so I hope I dont get crap for putting it in both places. I'm wondering if there is a way to enable high idle, on a 2011 duramax, with a remote start/alarm system? Is there an input on the ECM somewhere maybe?

 

I think the engine automagically kicks into high idle when you use the remote start in cold weather. I'll check for sure in the morning (I live in Minnesota).

[ColoradoSkiCountry]

I know that my Diesel will jump up about 200-300 RPM for about 30 seconds to a minute then back to normal when I start it cold in the morning...

[jro909]

i know you can get high idle set to the parking brake, when i drove ambulance it went into high idle as soon as the parking brake was set

[cfeiring]

On my Lmm, I can set an elevated idle that will increase the rpm at a set rate.

You have to set it to on via the DIC.

At a set temp ( do not remember ) when its cold outside and the engine is cold, it will elevate the rpms for a short time and mine does not matter if I remote start or key start after the engine has been running for approx. 30 seconds or so.

I first set it during the first winter and have not changed it.

 

It is not to be confused with the optional High idle that is variable, but for where I live and need it works but I do not live way up north like some of the other folks do.