CIRCUIT DESCRIPTION:
At the power up and after clearing DTCs, the TCM performs a self-test to determine if the calibration in memory is valid.
ACTION TAKEN WHEN THE DTC SETS:
1. DTC P0602 is stored in the TCM history.
2. The TCM does not illuminate the CHECK TRANS light (non-OBD II strategy).
3. The TCM returns to the boot program, and then waits to be recalibrated.
4. Transmission operates in hydraulic default, Reverse, Neutral, and 3rd ranges.
5. DTC is stored in the TCM history.
CONDITIONS FOR CLEARING THE DTC:
TCM must be recalibrated with a valid VEPS calibration.
Allison 1000 & 2000 Gen 5 Fault Code:P0563 System Voltage – High
Allison 1000 & 2000 Gen 5 Fault Code:P0562 System Voltage – Low
Allison 1000 & 2000 Gen 5 Fault Code:P0561 System Voltage – Performance
Allison 1000 & 2000 Gen 5 Fault Code:P0218 Transmission Fluid Over Temperature
Allison 1000 & 2000 Gen 5 Fault Code:P0123 Pedal Position Sensor Circuit – High Voltage
Allison 3000 & 4000 Gen 4 Fault Code: C1312 Retarder Request Sensor Failed Low
