Allison 1000 & 2000 Gen 4 Fault Codes: P0602 TCM Not Programmed

Allison 1000 & 2000 Gen 4 Fault Codes: P0602 TCM Not Programmed

CIRCUIT DESCRIPTION:
At the power up and after clearing codes, the Transmission Control Module (TCM) performs a self-test to determine if the calibration in memory is valid.

CONDITIONS FOR RUNNING THE DTC:
1. The components are powered and ignition voltage is greater than 9V and less than 18V (12V TCM) or greater than 18V and less than 32V (24V TCM).
2. This test will run before any TCM functions.

CONDITIONS FOR SETTING THE DTC:
DTC P0602 sets if the TCM determines the present calibration is invalid.

ACTION TAKEN WHEN THE DTC SETS:
1. DTC P0602 is stored in the TCM history.
2. The CHECK TRANS light illuminates.
3. The TCM returns to the boot program, and then waits to be recalibrated.
4. The TCM inhibits TCC engagement.

CONDITIONS FOR CLEARING THE DTC/CHECK TRANS LIGHT:
TCM must be recalibrated.

DIAGNOSTIC AIDS:
None