Transmission Control Module (TCM) - 8HP45

P0601-INTERNAL CONTROL MODULE MEMORY CHECKSUM ERROR

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The purpose of the diagnostic is to monitor the validity of the Read Only Memory (ROM) flash memory. A Cyclic Redundancy Check (CRC) checksum is calculated for each memory block of the flash memory and compared with the stored reference checksum. There is a different stored reference checksum for each memory block. If the checksum rationality check of the last memory block has finished, the calculation starts all over again beginning with the first memory block.

- When Monitored:
When the ignition switch is turned to the run position.

- Set Condition:
If the calculated checksum does not match the stored reference checksum for any of the memory blocks.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 8HP45 Pre-Diagnostic Troubleshooting Procedure
CHECK IF TCM IS FLASHABLE

NOTE: Controller is programmed with generic software and will not allow the correct vehicle Powertrain management.

1. With the scan tool, record the vehicles controller part number.
2. Select Use Controller Part Number under the Flash Tab.
3. Flash the controller with the correct software.

Were you able to update (flash) the controller successfully?

Yes

- Test Complete.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Using the schematics as a guide, check the Transmission Control Module Assembly (TCMA) connector terminals for corrosion, damage or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCMA. Valve Body - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.