Low Stall Speeds (Stall in Ranges 1-6). GMC Truck GMC Sierra Denali 2006

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 GMC Sierra Denali 🢒 Transmission/Transaxle 🢒 Automatic Transmission - Allison 🢒 Low Stall Speeds (Stall in Ranges 1-6)

Condition

Action

Engine not performing efficiently

•	Plugged or restricted injectors

•	High altitude conditions

•	Dirty air filters

•	Incorrect fuel/valve timing

•	Throttle linkage broken or not adjusted correctly

•	Electronic engine controls condition

Refer to the Engine section of this manual.

The following specific sections should be helpful in defining the condition:

•	Refer to Diagnostic System Check - Vehicle .

•	Refer to Symptoms - Engine Mechanical for the 6.6L (LLY).

•	Refer to Symptoms - Engine Mechanical for the 8.1L.

Stall speeds of 33% of normal implies freewheeling stator

Replace the converter assembly. Refer to Torque Converter Replacement .

Engine smoke controls

Compare lugback vs. static stall speed.

Incorrect torque converter

Install the correct torque converter. Refer to Torque Converter Replacement .