Transmission Overview
The 4L60E is an electronic version of the 700-R4 transmission. It uses two main solenoids to control shifting, and a converter clutch solenoid. These solenoids receive power whenever the key is on; the computer supplies ground to energize them. A pulsed EPC solenoid controls mainline pressure electronically.

Terminal Identification
Here’s a breakdown of the individual connector terminals:

Electronic Pressure Control
To check the electronic pressure control signal, connect your high-impedance voltmeter or signal monitor to the terminals shown.

Checking the Shift Pattern
Here’s how to connect your signal monitor to check the transmission shift signals:

And here’s the signal pattern you should see:

Forcing the Shift
Here’s the manual shift pattern you can expect with the transmission in failsafe:

And here’s how to force the 4L60E to shift electrically:

First Gear
In first gear, both shift solenoids receive ground.

Second Gear
To shift into second gear, the computer releases ground from solenoid A; only solenoid B is grounded.

Third Gear
To shift into third gear, the computer releases ground from solenoid B; neither solenoid is grounded.

Fourth Gear
To shift into fourth gear,the computer supplies ground only to solenoid A; the gray line shows the connection necessary to apply the converter clutch.

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