I have an LS3 connect and cruise combination. Something happened during installation and fried the original ECM according to HP Tech Line. I installed the new ECM but now transmission will not come out of low gear...wondering if there's a communication problem since we had to change the ECM? Any advice or help would be appreciated...
At least with my 4L60E, it'll at least run in a manually shifted D1, D2 and reverse in limp home mode. Find a wiring pinout diagram for your transmission and see what you have for volts, continuity and resistance on the pins in the fat, round connector.
With the ignition key on, you have no voltage on any pin on the fat round connector? What new ECM - identical to what was in your Connect & Cruise kit? Does your trans function in manually shifted D1? D2? Reverse?
The pins on the fat round connector are somewhat deep. Did you probe for them with a skinny multimeter probe to go deep enough to reach contact?
Rick
Last edited by B52bombardier1; 07-25-2019 at 05:13 AM.
I also had a bad VSS but it was original. It was only after I hooked up one of the Bluetooth phone apps for OBD II stuff (Dash Command or Torque Pro) that I saw it was running but zero MPH. Makes sense. If no speed, zero MPH, the trans thinks its sitting still. Why shift at zero MPH?