WOMS
P code powertrain Medium severity

P1568 Speed Control Unable to Hold Speed

The OBD2 code P1568 indicates that the vehicle's speed control system is unable to maintain the set speed, often due to a malfunction in the throttle control or related components

Definition

The OBD2 code P1568 indicates that the vehicle's speed control system is unable to maintain the set speed, often due to a malfunction in the throttle control or related components

Common causes

  • Faulty throttle position sensor (TPS)
  • Malfunctioning cruise control module
  • Damaged or frayed wiring in the cruise control system
  • Vacuum leaks in the intake system
  • Faulty brake pedal switch
  • Malfunctioning accelerator pedal position sensor
  • Issues with the engine control module (ECM)
  • Low battery voltage or electrical issues
  • Faulty cruise control actuator
  • Problems with the vehicle's speed sensor

Common misdiagnoses

  • Throttle position sensor failure
  • Cruise control switch malfunction
  • Faulty accelerator pedal position sensor
  • Wiring issues or shorts in the cruise control system
  • Engine control module (ECM) problems
  • Vacuum leaks affecting the cruise control system
  • Malfunctioning speed sensor
  • Transmission issues
  • Brake switch failure
  • Faulty cruise control actuator

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide additional context for the problem

  2. 2. Inspect the Throttle Position Sensor (TPS)

    The TPS is critical for the cruise control system. Check for proper operation and ensure that it is calibrated correctly. Look for any signs of damage or wear

  3. 3. Examine the Cruise Control Switch

    Ensure that the cruise control switch is functioning properly. A faulty switch can prevent the system from engaging or maintaining speed

  4. 4. Inspect Wiring and Connectors

    Check the wiring and connectors related to the throttle control and cruise control systems for any signs of damage, corrosion, or loose connections

  5. 5. Check the Brake Pedal Position Sensor

    The cruise control system is designed to disengage when the brake pedal is pressed. Ensure that the brake pedal position sensor is functioning correctly

  6. 6. Inspect the Throttle Body

    Check for any obstructions or carbon buildup in the throttle body that could affect its operation. Clean the throttle body if necessary

  7. 7. Test the Cruise Control Module

    If applicable, test the cruise control module for proper operation. This may require specialized diagnostic equipment

  8. 8. Check for Vacuum Leaks

    If the vehicle uses a vacuum-operated cruise control system, inspect for any vacuum leaks that could affect performance

  9. 9. Review the Vehicle's Speed Sensor

    Ensure that the vehicle speed sensor (VSS) is functioning correctly, as it provides speed data to the engine control module (ECM) and cruise control system

  10. 10. Inspect the Engine Control Module (ECM)

    In some cases, the ECM may have software issues or require reprogramming. Check for any available updates or recalls. 1

  11. 11. Perform a System Reset

    After addressing any identified issues, clear the trouble codes and perform a test drive to see if the problem persists. 1

  12. 12. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the P1568 code for your specific make and model, as manufacturers may have specific fixes or recommendations. If the issue persists after following these steps, it may be advisable to consult a professional mechanic or technician for further diagnosis and repair