Originally Posted by
Jon S.
The P0606 DTCs is one of those codes that may be set by several issues - it is not limited to a defective ECM. A mismatch between the APP (accelerator pedal), throttle body, and ECM calibration can also set this DTC.
A 6.2L in a Colorado makes for a great driver !
The 2009 Colorado would have originally used an E67 ECM - which is helpful. You could reuse your original E67 ECM, if you had it flashed with a 2009 Colorado 5.3L calibration. This would also allow you to retain the existing 2009 Colorado APP.
The manual transmission will cause the most issues and compromises. A 4-speed auto or 6-speed auto would have been a more conversion friendly choice.
You mentioned using an OEM wiring harness. For what application ?