What it means
The control module detected that vehicle speed exceeded its calibrated overspeed threshold. This code does not by itself mean a speed limiter or fuel cut was activated.
At a glance
- Usually lights the check-engine light
How it works
The control module monitors vehicle speed, usually from one or more wheel-speed or transmission speed signals. P0297 is stored when the reported speed exceeds the module’s calibrated overspeed threshold; the code alone does not show that the vehicle activated a speed limiter or cut fuel.
Common causes
Most likely first.
- Vehicle speed exceeded the calibrated threshold
- Vehicle speed signal or wiring fault
- Control-module or calibration fault
Symptoms
- Check-engine light, if commanded
- Overspeed warning, if equipped
How to diagnose it
- Review freeze-frame data and other stored codes to determine the recorded speed and whether the event coincided with a signal fault.
- Compare scan-tool vehicle-speed data with the dashboard reading and, when safe, a reliable independent speed reference.
- Inspect the relevant vehicle-speed sensor wiring and connectors for damage, looseness, or corrosion.
- If scan data shows an implausible speed, check the affected sensor and signal circuit using the manufacturer’s diagnostic procedure.
- If the speed signal is credible but the code recurs under normal conditions, verify module calibration and related control-module faults against manufacturer information.
Common fixes
- Repair damaged or corroded vehicle-speed sensor wiring or connectors.
- Replace a vehicle-speed sensor only if testing confirms it is faulty.
- Correct a verified module calibration issue using the manufacturer’s approved procedure.
- Address any confirmed control-module fault.
Can I keep driving?
If the vehicle was actually driven above the legal or safe speed, slow down and avoid repeating that condition. If the speed reading was implausible, have the signal checked before relying on the speedometer or driver-assistance features.
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.