OBD-II code · Powertrain (generic)
P07BF Input/Turbine Shaft Speed Sensor A Circuit Low
Input/turbine shaft speed sensor A signal voltage below the lower limit — short to ground or open supply. Without this signal the TCM cannot calculate slip across the torque converter or first gear element.
Is it safe to drive with P07BF?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Input Shaft Speed Sensor A, Sensor Wiring
Related codes
- P07C1Input/Turbine Shaft Speed Sensor B Circuit Low
- P07C3Input/Turbine Shaft Speed Sensor C Circuit Low
- P07BCTransmission Park Position Sensor/Switch B Circuit Performance High
- P07BDTransmission Park Position Sensor/Switch B Circuit Intermittent/Erratic
- P07BETransmission Park Position Sensor/Switch A/B Correlation
- P07C0Input/Turbine Shaft Speed Sensor A Circuit High
- P07C2Input/Turbine Shaft Speed Sensor B Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.