Allison LCT1000 TCM Ignition Power Feed Missing at TCM Connector C1 Terminal 2 - delay default drive DTC engage first forward gear hesitate information inoperative intermittent LCT 1000 loss MIL P0561

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

The automatic transmission controls schematic for power and ground shows circuit 1020 coming from ignition fuse 0 to TCM connector C1 terminals 2 and 4. The wiring harness on the truck does not have a wire in the terminal 2 cavity.

Circuit 1020 was eliminated from TCM connector C1 terminal 2 at the start of production for the 2003 model year.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.