2018 Toyota Prius C Cruise Control Isn't Working

Common Causes of Cruise Control Malfunctions in Your 2018 Toyota Prius C and How to Fix Them

Find Repair Location
Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
30% chance it's the
Sensor
0%
25% chance it's the
Control Module
0%
25% chance it's the
Throttle
0%
20% chance it's
Something else
The most common reasons a 2018 Toyota Prius C cruise control isn't working are failed control module, sensor or switch issues, or throttle actuation problems.
  • Sensor: A faulty or malfunctioning sensor can lead to incorrect readings, causing issues with engine performance or other systems relying on accurate data.
  • Control Module: A faulty control module can lead to erratic vehicle behavior or failure of various electronic systems due to improper signal processing.
  • Throttle: A faulty throttle body or a defective accelerator pedal position sensor may be causing inconsistent throttle response.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2018 Toyota Prius C cruise control isn't working?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

In the event that a wheel speed sensor fails, the ABS, traction control system (TCS) and manufacturer specific stability control system lights will illuminate, informing the driver that the systems are disabled. The vehicle will be more prone to tire slip, and normal driving patterns may need to be adjusted to correct for the loss of computer control. On older vehicle's, the speedometer can be affected, causing illumination of the check engine light as well.

The cruise control switch can cause complete failure of the cruise control feature, but in a lucky scenario only partial functionality will be lost. This means that the cruise control may come on, but that it will not increase in speed automatically, or the cancel button does not work leading the driver to cancel cruise control with the foot brake. In some vehicles, the cruise control light may illuminate, or a warning message may be displayed due to lack of functionality.

What are the steps to diagnose the cruise control issue in a 2018 Toyota Prius C?

To effectively diagnose a cruise control issue in a 2018 Toyota Prius C, it's essential to adopt a systematic approach that begins with the simplest potential problems before progressing to more complex diagnostics. Start by checking the cruise control fuse, as a blown fuse can easily disrupt the system's functionality. Next, inspect the cruise control buttons on the steering wheel to ensure they are operational, since faulty buttons can lead to engagement issues. Utilizing an OBD-II scanner to scan for error codes is a crucial step, as these codes can reveal underlying problems within the cruise control system. Following this, verify the functionality of the vehicle's speed sensors, which are vital for the cruise control to operate correctly; any faults here can significantly impact performance. Additionally, examine the wiring and connections associated with the cruise control system for any signs of damage or corrosion, as poor connections can lead to failures. Finally, test the cruise control module itself to confirm it is functioning properly, as a malfunctioning module can prevent the system from engaging altogether. By following this structured diagnostic approach, you can efficiently identify and address the root cause of the cruise control issue in your Prius C.

What are the common problems that could cause the cruise control to stop working in a 2018 Toyota Prius C?

When the cruise control in your 2018 Toyota Prius C stops functioning, it can be frustrating, but understanding the common problems can help you troubleshoot effectively. One of the primary culprits is a faulty brake pedal switch, which is crucial for disengaging the cruise control when the brake is applied. If this switch malfunctions, it may prevent the system from engaging at all. Additionally, issues with the speed sensor can disrupt the cruise control's ability to maintain speed, as it relies on accurate readings to operate correctly. Another potential issue is a blown fuse; checking the fuses related to the cruise control system is a simple first step that can often resolve the problem. Furthermore, a malfunctioning throttle actuator can hinder the system's performance, as it controls the engine speed necessary for maintaining a set speed. Lastly, problems with the Electronic Control Module (ECM) can also lead to cruise control failure, as this component manages various vehicle functions, including cruise control. By systematically checking these components, you can identify and address the issue, restoring functionality to your cruise control system.

How urgent is it to address the malfunctioning cruise control in a 2018 Toyota Prius C?

Addressing a malfunctioning cruise control in a 2018 Toyota Prius C is not just a matter of convenience; it is a critical safety concern that requires immediate attention. When cruise control fails, it can lead to unpredictable vehicle behavior, such as sudden acceleration or deceleration, which significantly increases the risk of accidents. Moreover, a malfunctioning system can detract from the overall driving experience, making it challenging to maintain a steady speed, especially during long trips. Ignoring these symptoms can result in further damage to the vehicle's systems, leading to more extensive and costly repairs. Therefore, it is essential to prioritize a diagnostic check by a qualified mechanic to identify the root cause of the issue. If the vehicle is still under warranty, seeking assistance from an authorized Toyota service center is advisable to ensure that repairs are covered. In summary, the urgency of addressing cruise control malfunctions cannot be overstated, as it directly impacts both safety and vehicle integrity.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.

2018 Toyota Prius C Cruise Control Issues & Repairs