ECM and TCM Power Mode Backup Strategy
The ECM and TCM remain in the last known power mode state until it can determine its backup system power mode based on their discrete Accessory voltage and Run/Crank Ignition 1 voltage inputs.
| Accessory Voltage State | Run/Crank Ignition 1 Voltage State | Power Mode Determined |
|---|---|---|
| Inactive | Inactive | Off |
| Active | Inactive | Accessory |
| Active | Active | Run |
| Inactive | Active | Crank |