This is a very interesting “How to Diagnose, Clean and/or Replace the Shift Solenoids in the GM 4L60E- 4l65E Transmissions” involving a Hands On Diagnosis for a 'Limp Mode Condition' of starting off in 3rd Gear on an Australian Holden (of all things) presenting with 1-2 Shift Issues.
What is also DIFFERENT about this Video is that the VOP (Video Original Poster) uses a Unique Brass Tool and Retention Clip that allows him to pneumatically pressurize each Solenoid while analyzing them Electrically, testing for Coil EMF Strength and internal Check Valve against Fluid Leakage in a Bench Top Setting at Less than Optimum Battery Voltage.
He also is fastidious when Cleaning and Flushing out the delicate Gold Plastic Switches within the Black Manifold Switch Plate. This is a Very Comprehensive and Instructive 20 Minutes (10 @ 2X if you’re in hurry):
What is also DIFFERENT about this Video is that the VOP (Video Original Poster) uses a Unique Brass Tool and Retention Clip that allows him to pneumatically pressurize each Solenoid while analyzing them Electrically, testing for Coil EMF Strength and internal Check Valve against Fluid Leakage in a Bench Top Setting at Less than Optimum Battery Voltage.
He also is fastidious when Cleaning and Flushing out the delicate Gold Plastic Switches within the Black Manifold Switch Plate. This is a Very Comprehensive and Instructive 20 Minutes (10 @ 2X if you’re in hurry):