What it means
The input/turbine shaft speed sensor C circuit signal is below the expected range.
At a glance
- Usually lights the check-engine light
How it works
Input/turbine shaft speed sensor C reports shaft-speed information that the control module uses to manage transmission operation. This code sets when sensor C's circuit signal is below its expected low-side range, potentially because the signal is shorted to ground.
Common causes
Most likely first.
- Signal wire shorted to ground
- Connector pins corroded - high contact resistance
- Harness 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
How to diagnose it
- Read freeze-frame and live data to compare sensor C speed with other available speed readings and identify when its signal went low.
- Inspect sensor C's connector and harness for chafing, exposed wire, corrosion, and loose terminals that could pull the signal toward ground.
- Use the wiring diagram to check the C signal wire for a short to ground and inspect its supply and ground connections.
- Check whether the sensor C reading changes plausibly as the shaft turns using available scan data or the vehicle's service procedure.
- If the wiring is sound, test sensor C and the module input against the manufacturer's specification.
Common fixes
- Reconnect or clean sensor C's connector if contact is poor.
- Repair chafed wiring or a signal wire shorted to ground.
- Restore a damaged sensor C supply or ground connection.
- Replace input/turbine shaft speed sensor C if it fails output testing.
- Repair the transmission control module input circuit if the sensor and harness pass testing.
Can I keep driving?
Limit driving if the transmission shifts harshly, slips, or delays engagement, and avoid towing or heavy loads. If shifting becomes unpredictable or the transmission locks into a gear, stop and arrange a tow to reduce the risk of 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.