TCM Power Input Signal Low
TCM main supply voltage falls below the operating threshold for an extended period, causing reset risk and unreliable shift control.
Affected components
- Tcm
- Battery
- Wiring harness
Common causes
- High likelihood: Discharged or weak battery
- Medium likelihood: Voltage drop in supply wiring
Possible symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.