P0297 code definition
The P0297 code indicates that the car has been driven beyond the maximum speed to which it has been calibrated.
What the P0297 code means
The P0297 code means that the car has been operated at a speed exceeding its maximum calibration setting. With most automakers this is 100 mph. A wheel speed sensor or the speed sensor will notify the PCM of the vehicle’s overspeed condition, and the PCM will set a code.
What causes the P0297 code?
The most common cause of the P0297 is the driver operating the vehicle at too high of a speed. Because most cars have a limiter that disallows acceleration beyond a certain point, some drivers will accelerate to the limit and then coast downhill to attain higher speeds. However, this will result in the P0297 code being set and sometimes in the Check Engine Light turning on. The vehicle’s speed is constantly monitored by several sensors (wheel speed sensors, as well as the vehicle speed sensor), and the code will be set as soon as a limit has been surpassed. However, in some instances, a faulty speed sensor is to blame.
What are the symptoms of the P0297 code?
There are no symptoms associated with the P0297 code other than the Check Engine Light coming on in the dash.
How does a mechanic diagnose the P0297 code?
In order to diagnose the P0297 code, the mechanic will connect an OBD II scanner to the car’s computer and read the codes stored there. He or she will then clear the codes and test drive the vehicle to determine if they will reset. If it does not, then the most likely cause is the driver operating the car at speeds that exceed the automaker’s preset limitations. However, if the code does reset at normal driving speeds, further diagnosis is needed.
The next step is to use a scanner to view the vehicle speed sensor data. This is accomplished by having a helper drive the car while the mechanic reads the data on the scanner. If the speed sensor sends erratic signals, or if the signal does not change with acceleration or deceleration, the problem is most likely a faulty speed sensor.
Common mistakes when diagnosing the P0297 code
The most common mistake here is replacing the vehicle speed sensor without fully diagnosing the problem. The most frequently found cause of the P0297 code is the vehicle being driven too fast, rather than electrical problems or sensor failure. Replacing the sensor will not solve the problem, and the code will reset the next time the driver exceeds the speed limitation set by the automaker.
How serious is the P0297 code?
Generally, the P0297 code is not particularly serious, as long as it is related to an actual overspeed situation. In this case, the code can be cleared, and as long as the vehicle is not driven at high speeds, it will not return. However, if the speed sensor is the problem, it should be replaced as soon as possible, because it will affect everything from the speedometer readout to engine operation.
What repairs can fix the P0297 code?
The most common repair here is to clear the code and explain to the driver not to exceed speed limitations. However, replacing the speed sensor may be necessary, or there could be shorts or opens within the sensor’s circuit that must be repaired.
Additional comments for consideration regarding the P0297 code
The most common cause of the P0297 code is driver error. This must be ruled out completely before replacing parts.
Need help with a P0297 code?
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