What it means
The input/turbine shaft speed sensor B circuit signal is above the expected range.
At a glance
- Usually lights the check-engine light
How it works
Input/turbine shaft speed sensor B supplies speed information for transmission shift control. This code sets when sensor B's circuit signal is higher than the expected high-side range, which can occur if the signal is connected to a voltage source.
Common causes
Most likely first.
- Signal wire shorted to reference voltage
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
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
How to diagnose it
- Read freeze-frame and live data to check sensor B speed and the conditions when the signal exceeded its expected range.
- Inspect sensor B's connector and harness for pinched or damaged insulation, corroded pins, and contact with a powered wire.
- Use the wiring diagram to check the B signal for a short to reference voltage or battery voltage and inspect its circuit connections.
- Observe whether sensor B reports a plausible changing speed as the shaft turns, using the vehicle's supported scan data or service procedure.
- If wiring checks out, test sensor B and the control module input against the manufacturer's specification.
Common fixes
- Reseat or clean sensor B's connector if its contacts are poor.
- Repair wiring shorted to reference voltage or battery power.
- Replace pinched or damaged wiring in sensor B's circuit.
- Replace input/turbine shaft speed sensor B if its output stays high.
- Repair the transmission control module input circuit if tests point to the module.
Can I keep driving?
Avoid heavy loads and limit driving if the transmission shifts harshly, slips, or responds unpredictably. Stop and arrange a tow if it cannot maintain safe, predictable shifting, since continued driving can cause further damage.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.