The P0590 trouble code is a diagnostic trouble code (DTC) that indicates a problem with the cruise control system, specifically relating to the “Multi-Function Input ‘B'” circuit. This code is typically triggered when the Powertrain Control Module (PCM) detects that the cruise control multi-function input circuit is either stuck or not functioning correctly. The cruise control system is designed to maintain a vehicle’s speed without the driver needing to keep their foot on the accelerator pedal, providing convenience during long drives. Understanding and addressing this code is essential for ensuring that the cruise control system functions properly.
| P0590 Code Meaning | P0590 Code Common Causes |
|---|---|
| Cruise Control Multi-Function Input ‘B’ Circuit Stuck | Faulty multi-function switch |
| Electrical issue in the cruise control circuit | Damaged wiring or connectors |
| Malfunctioning cruise control module | Corroded or loose connections |
| Faulty brake pedal position sensor | Water intrusion in electrical components |
| Faulty accelerator pedal position sensor | Internal issues within the PCM |
Symptoms of P0590 Code
When dealing with a P0590 code, vehicle owners may notice several symptoms that can indicate problems with the cruise control system:
- Check Engine Light: The illumination of the check engine light on the dashboard is often the first sign of trouble.
- Cruise Control Inoperative: The cruise control system may fail to engage or operate as intended.
- Erratic Speed Control: Sudden changes in vehicle speed while cruise control is active can occur, leading to inconsistent performance.
- Cruise Control Light Malfunction: The cruise control indicator light may remain illuminated regardless of whether the system is engaged.
- Blown Fuses: It’s common for blown fuses to accompany this trouble code, indicating an electrical issue.
Understanding P0590 Code
The P0590 code specifically relates to issues within the cruise control multi-function input circuit “B.” This circuit processes various signals from different components, including the brake pedal position sensor, accelerator pedal position sensor, and vehicle speed sensor. If any of these components send incorrect signals or if there are wiring issues, the PCM will trigger the P0590 code.
Technical Explanation
The cruise control system relies on a series of inputs to maintain vehicle speed. When you set your cruise control, signals from these inputs are sent to the PCM, which adjusts throttle position accordingly. If any input signal is stuck or malfunctioning, it can prevent proper operation of the cruise control system.
The “B” designation in P0590 does not refer to a specific component but rather indicates a particular section of the circuit that is experiencing issues. Diagnosing this code involves checking each component and connection in that circuit.
Step-by-Step Diagnosis
Diagnosing a P0590 trouble code involves several systematic steps:
- Visual Inspection: Begin by visually inspecting all wiring and connectors associated with the cruise control system for signs of damage, corrosion, or loose connections.
- Use an OBD-II Scanner: Connect an OBD-II scanner to retrieve diagnostic codes and freeze frame data. This will help identify any additional codes that may be present alongside P0590.
- Check Input Signals: Monitor signals from the brake pedal position sensor, accelerator pedal position sensor, and other relevant inputs using a multimeter.
- Test Components: Test each component in the circuit for functionality:
- Check if the multi-function switch operates correctly.
- Inspect sensors for proper operation.
- Use a digital volt/ohmmeter to assess wiring integrity.
- Clear Codes and Retest: After repairs are made, clear any stored codes and take the vehicle for a test drive to see if P0590 reappears.
Solution Methods
Addressing a P0590 trouble code typically involves one or more of the following solutions:
- Replace Faulty Components: If testing reveals that any component (like the multi-function switch or sensors) is faulty, replace it with a new part.
- Repair Wiring Issues: If damaged wiring or connectors are found, repair or replace them as necessary to restore proper function.
- Inspect and Clean Connectors: Corroded connectors should be cleaned or replaced to ensure good electrical contact.
- Update PCM Software: In some cases, updating or reprogramming the PCM may resolve software-related issues causing erroneous readings.
Cost Estimates
The cost for diagnosing and repairing a P0590 trouble code can vary significantly based on several factors:
- Diagnostic Fees: Expect to pay between $100 to $150 for a professional diagnostic service using an OBD-II scanner.
- Parts Replacement Costs:
- Multi-function switch replacement can range from $50 to $200.
- Wiring repairs might cost between $20 and $100 depending on labor rates and parts required.
- Sensor replacements typically range from $50 to $150 each.
Overall repair costs can range from $100 for simple fixes (like blown fuses) up to $500 or more for comprehensive repairs involving multiple components.
Warnings and Recommendations
- Always ensure that you follow safety precautions when working on your vehicle’s electrical systems. Disconnecting the battery before beginning any electrical work is advisable.
- If you are not comfortable diagnosing or repairing electrical issues yourself, seek professional assistance from a certified mechanic. Electrical problems can be complex and may require specialized tools and knowledge.
Closing Paragraph
In summary, understanding and addressing the P0590 trouble code is crucial for maintaining your vehicle’s cruise control functionality. By following systematic diagnostic steps and being aware of potential symptoms and causes, vehicle owners can effectively troubleshoot this issue. While some repairs may be manageable for DIY mechanics, others may require professional intervention to ensure safety and reliability on the road.
Frequently Asked Questions About P0590
- What does error code P0590 mean?
P0590 indicates that there is an issue with the Cruise Control Multi-Function Input ‘B’ Circuit being stuck. - Can I drive my car with a P0590 code?
Yes, but it will likely disable your cruise control system until repaired. - What are common symptoms of P0590?
Common symptoms include check engine light illumination, inoperative cruise control, and erratic speed behavior. - How do I fix error code P0590?
Fixing this error usually involves inspecting wiring, replacing faulty components like switches or sensors, and ensuring all connections are secure. - Is P0590 a serious problem?
P0590 itself is not serious but can affect driving comfort; however, underlying electrical issues could worsen over time. - How much does it cost to repair P0590?
The cost can range from $100 for minor fixes up to $500 or more for extensive repairs depending on parts needed. - Can I reset P0590 myself?
You can reset it using an OBD-II scanner after repairs; however, if it returns, further diagnosis is needed. - Should I consult a professional for P0590?
If you’re unsure about diagnosing electrical issues or if repairs seem complex, it’s best to consult a professional mechanic.