18-071-16

Flash: Powertrain Diagnostic and System Improvements This bulletin involves reprogramming the Powertrain Control Module (PCM) with updated software. The technician may find the following Diagnostic Trouble Code (DTC) set in the Powertrain Control Module (PCM) memory: · **U0140 - Lost Communication With Body Control Module.** Some customers may experience any of the following: · **2 - 1 downshift clunk or bump (JC vehicles).** · Long crank times when temperature is between -6°C and -3°C (20°F and 25°F) and 15°C and 18°C (60°F and 65°F). · Engine RPM fluctuation on closed throttle deceleration between 48 KPH and 32 KPH (30 MPH and 20 MPH). · Slightly elevated RPM (100 RPM) while driving slow or parking lot driving conditions (JC vehicles). Updating the PCM software will correct the conditions listed above.