The OBD II trouble codes define many kinds of issues with a vehicle. If you want to understand your vehicle’s problem, you must first identify the signals. Then you have to locate the OBD II trouble codes. The C1233 is a code related to the left front wheel speed sensor. You can get the result of any problem related to the chassis by the ABS sensor. The ABS light is a reflection of the issues. When the sensor identifies the issues, the ABS light turns on. Then, you have to check the OBD II scanner. When it shows the C1233 trouble code, you can easily understand that the input signal of the left front wheel speed sensor is missing.
Symptoms:
- ABS light on
- The traction control system malfunctioned
- Speedometer issues
- Possible loss of anti-lock brake system functionality
- Increased braking distance
Possible Solutions:
- Inspect and clean the wheel speed sensor and its connector
- Replace the faulty wheel speed sensor
- Repair or replace damaged wiring and connectors
- Check for proper sensor alignment
- Inspect the tone ring for damage or debris
- Check the wheel bearing condition
- Update or reflash ABS module software if necessary
- Replace the ABS control module if it’s faulty (rare)
What is The Left Front Wheel Speed Sensor?
The left front wheel speed sensor is a part of the ABS. It is also called an ABS sensor. Do you know where you will find the sensor? If there is any sensor problem, you must repair or recheck it. It is located on the tire of the left front wheel. There is a bit of difference in the sensor’s location between the front tires and the rare tires. The sensor of the front tires is near the brake rotors. On the other hand, you will get it on the rare end housing for the rare tires.
How can the input signal of the left front wheel speed sensor be missing?
The ABS module works for the perfect braking system of a vehicle. It takes the signal for measuring the wheel speed and gives the brake pressure through the speed measurement. The sensor ring has a magnetic field. The wheel speed sensor can detect the area to pass the face of the active wheel speed sensor. Thus, it affects the ABS to give the perfect brake pressure for an effective braking system.
The input signal of the speed sensor is so valuable for efficient braking. The signal goes to the ABS to measure the speed and maintain the appropriate pressure for braking the vehicle. Suppose the car is going at an over speed. Can your braking system control it by giving a little pressure? Not at all, because the braking system must have the ability to stop the car with the whole brake pressure. So, the ABS signal helps it apply adequate force to stop the vehicle quickly. The lack of correlation between the sensor and ABS occurs in the absence of the input signal.
The Common Causes of The Trouble Code C1233
The OBD II trouble code C1233 is related to the input signal of the left front wheel speed sensor. It is harmful to a vehicle. The issue can destroy your life by presenting a wrong signal. Can you imagine what can happen if the sensor cannot identify the brake pressure and the ABS can not brake forcefully? The system will not be able to brake the vehicle when you need it strongly. Here I am presenting some common causes and problematic situations of the C1233.
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Damaged Wheel Speed Sensor
The damaged or faulty wheel speed sensors can not work perfectly. They are the reason for causing harmful effects to the vehicle. As a damaged sensor can not identify the signal correctly, it is also a significant reason for missing the input signal. Consequently, the ABS fails to control the vehicle instantly.
The ABS control module is essential for the effective braking system of the ABS. It is a microprocessor in a vehicle. The module works for checking the vehicle’s speed and the power of the ABS. Then it adjusts the ABS power with the vehicle’s speed. When the control module becomes damaged or fails to work, the input signal becomes missing. Thus the OBD II scanner shows the error code C1233.
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Damaged Reluctor Ring
The reluctor ring is mounted on the vehicle’s wheel and connected to the ABS. When the circle becomes damaged, it hampers the braking system and creates an effect of causing harm. The damaged ring will disappoint you by generating the input signal missing. So, it is also a significant cause of the C1233 code. 
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Gathering of Debris on the Reluctor Wheel
The reluctor wheel should be neat and clean. Every vehicle user has to keep the wheel clean for better use. But, if you have no concentration on cleaning the wheel, it becomes unable to use safely. Day by day, it becomes damaged, and the input signal of the left front wheel speed sensor will be missing. Therefore, it is not a surprising matter for you to get the C1233 trouble code.
The Symptoms of The OBD II Trouble Code C1233
How can you identify that your vehicle is problematic and shows the C1233? The OBD II scanner will show you the result. But, is there any sign to identify the issues related to the C1233? Yes, you can observe some simple things and understand that your vehicle is problematic.
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ABS Light On
The ABS light indicates the vehicle’s problems. When the light turns on, you can easily understand that something is happening to create any problem with your car. After that, you can check the problem with your OBD II scanner and get the result to be sure. The scanner gives you surety; the ABS light is a symptom. When it turns on, you get the sign of a problem and prepare yourself to repair the vehicle.
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Engine Light On
The engine light is another indication of the vehicle’s problems. All of the chassis problems have a common symptom- they show their existence by turning on the engine light. So, when the light turns on, you can easily understand that some problem is occurring in your vehicle. Take an OBD II scanner to check the situation and take steps to solve it.
Diagnose Cost of The OBD II Code C1233
Some varieties of factors determine the reasonable cost of diagnosis of your C1233. The elements are location, type of vehicle, model, and even the vehicle’s engine type. Generally, $70 is the lowest cost. You can take the service of up to $150 as the standard of service. 
Can I Remove the C1233 Code by Exchanging the RF and the LF Wheel Harness?
Since the problem is related to the wheel speed sensor, you can not remove the C1233 code interchanging the harnesses. If you do that, you will find that the saddles are exchanged, but the problem is not solved. Still, you are getting the trouble code on the OBD II scanner. So, if you want to fix the problem and remove the OBD II trouble code C1233, you have to replace or repair the speed sensor, not exchange the harnesses.
Final Thoughts
The active wheel sensor can generate a signal. It sends the signal to the ABS module to brake perfectly. It is incredible to determine the appropriate pressure of ABS according to the wheel’s speed. The system makes braking system is perfect for any velocity of the car. When the input signal is missing, naturally, the driver will face a considerable problem. He will lose the balance of braking, and as a result, it can cause an accident. Finally, the OBD II code C1233 indicates the input signal missing problem and makes you ready to repair it soon.
Kevin Nicholas is an automotive technician who is a genius at software and hardware-related issues. He manually tested more than a hundred OBD scanners and gave his honest opinion on whether the device was worth the money or not. His in-depth OBD review articles help people choose the right product, whether it is a European, American, or Asian vehicle. He completed his Automotive Specialized Training Course at Universal Technical Institute and has more than 15 years of experience in the field.
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