This bulletin applies to 2009-2018 Chevy Impala models equipped with automatic transmissions. Some customers may comment that the MIL lamp is on. In “rare” cases, they may also note that there is no PRNDL display.
When checking for DTCs, technicians may find P182E (internal mode switch indicates invalid range) set as active or history in the transmission control module (TCM).
Verify proper shift cable adjustment. Verify proper ECM Park/Neutral switch status in all ranges. Verify proper internal mode switch (IMS) A/B/C/P parameters in all ranges. Perform the diagnostic repair verification after completing any repairs.
Note: If DTC U0101 is set as active or history in the electronic brake control module, it should be ignored, as it has been found to be falsely setting.