21-009-20

Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the latest available software. Some customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following DTCs: P1DDE-00 - Ignition Run-Start Input 1-2 Correlation(Sales Code DFR Only). P1DF3-00 - ECU Not Initialized(Sales Code DFR Only). P0733-00 - Gear 3 Shift Incorrect Ratio (while operating in 4-Lo range). P0716-00 - Input Shaft Speed Sensor 1 Performance. P0721-00 - Output Shaft Speed Sensor Circuit Performance. P1DB6-00 - Vehicle Speed Signal Performance. P1DAB-00 - Vehicle Speed Undetermined. P215C-00 - Output Shaft Speed Wheel Speed Correlation. P0607-00 - ECU Internal Performance. P1DAC-00-Engine Speed Undetermined. P07BF-00 - Input/Turbine Shaft Speed Sensor 1 Circuit Low. P07C0-00 - Input/Turbine Shaft Speed Sensor 1 Circuit High. P077C-00 - Output Shaft Speed Sensor Circuit Low. P077D-00 - Output Shaft Speed Sensor Circuit High. P177F-00 - Output Shaft Speed Sensor Out Of Range High. P1778-00 - Input-Turbine Shaft Speed Sensor A Out Of Range High. P0731-00 - Gear 1 Shift Incorrect Ratio. P0979-00 - Shift Solenoid 3 Control Circuit Low. P1DCD-00-TCM Monitoring Processor Performance Multiple Clutches Locked Up. In addition, the following software enhancements are also available:Auto-start Improvements. Low speed coast down bump improvements. Tip in bump improvements. Bump during tow/haul high throttle acceleration. Gear hunting during cruise resume. Gear hunting during uphill trailer tow. Cruise control under-speed during uphill trailer tow. Gear hunting during highway speed operation. Hang in gear when driver desires earlier upshift/lower engine speed operation. Coast-down downshift improvements for 6-5, 5-4 and 4-3. Coast-down downshift improvements for 2-1. Cold temperature downshift improvements for 6-5 and 4-3. Cold temperature upshift improvements for 1-2, 2-3, 3-4