Can anyone tell me how the 3cyl warmup works how does it stop the other 3 cyl.

 

Stolen from...
http://dodgeram.info/tsb/2001/18-019-01.htm

(I would have to say that since timing is controlled by the fuel pump since there are no spark plugs or ignition system, per say. That the fuel pump just does not supply fuel to the cyl that are to be shut down.)


Once enabled, idle speed will slowly ramp up from 800 rpm to 1200 rpm when all of the following conditions are met:

1. Intake Manifold Temperature less than 0°C (32°F) and,
2. Coolant Temp is less than 60°C (140°F) and,
3. The Transmission is in Neutral or Park and,
4. The Service Brake pedal is not depressed and,
5. Throttle = 0% and,
6. Vehicle Speed = 0 mph

Additionally, if Intake Manifold Temperature (IMT) is less than -9°C (15°F), and all of the parameters above are met, three of the cylinders will be shut off upon reaching 1200 rpm, creating a slight change in engine sound which is normal. This allows the engine to create increased heat in the cooling system, allowing more rapid engine warm up and cab heating.

Both features will automatically disable when one of the following occurs:

1. The Automatic Transmission is placed in gear (forward or reverse) or,
2. The Service Brake pedal is depressed or,
3. Throttle position is greater than 0% or,
4. Vehicle Speed is greater than 0 mph or,
5. Coolant Temperature is greater than 79°C (175°F).

Engine speed will return to normal operation at 800 rpm. If the engine continues to idle and coolant temperature is at or below 60°C (140°'F), the feature will reenable. In order to operate properly, the Accelerator Pedal Position Sensor (APPS) must stay at idle.

NOTE: ANY TYPE OF AFTERMARKET IDLE SPEED KICKER THAT ACTIVATES THE APPS WILL DISABLE THIS FEATURE.

 

Thanks stacks I just wondered how it worked D.C.

 

"Slight change in engine sound", the first time mine went to 3cyl idle I almost jumped in and shut it off it sounded so brutal.

 

I did!!!...........