It is attached to the rear of the ECM under the hood near and under the battery on the 4L60-E /4L65-E and 4L70-E on the late 07 and a few early 08s. If yours has the 6 speed transmission it is inside the transmission mounted to the solenoid and control pack on the valve body. The external one is easy to replace, you disconnect the two connectors and unclip it from the bracket. Then clip the replacement into place and use a scan tool to program it. If you are simply removing it and putting it back into place you don't need to use the scan tool.
On the 6 speed it's a bit harder as the unit is internal to the transmission, instructions are in the last 4 images. You do need to drop the fluid and pan for access and I would change out the filter and the wiring harness inside either transmission design as both have a bad habit of leaking transmission fluid out into the connector housing and causing problems.
Images (Click to enlarge)
Mar 25, 2021 at 4:23 PM
