The 6T30/40/45/50 transmission uses a pressure control system to apply and releaseclutches during shifts. The transmission control module (TCM) controls pressure commandsto the pressure control solenoids.
As normal wear of the transmission clutches occur, the TCM performs a clutch functionverification. The TCM momentarily commands a clutch on at a low pressure. The clutchfunction verification is conducted on smooth roads when the transmission is not shiftingand engine torque is consistent and positive.
When a clutch function verification is occurring, a slight bump or drag may be detectedmomentarily. The clutch function verification will occur a few times over severalminutes and will not repeat again for a thousand or more miles. This is a normalcondition and no repair attempts should be performed.
The clutch function verification will be performed sooner for a particular clutchif the TCM detects it is producing frequent poor shift control.
3-5-Reverse and 4-5-6 Clutch Housing Disassemble (6T40/45/50 - Gen 2) Automatic Transmission Unit
Transmission Adaptive Functions Automatic Transmission UnitCamshaft Position Intake Actuator Replacement Valvetrain Camshaft
Special ToolsEN-45059Angle MeterEN-48749Timing Chain Retention Tool KitEN-48953Camshaft Actuator Locking ToolFor equivalent regional tools, refer toSpecial Tools.Removal ProcedureRemove the air cleaner assembly. Refer toAir Cleaner Assembly Replacement.Remove the camshaft cover. Refer toCamshaft Cov ...