The P0585 code is a diagnostic trouble code (DTC) that indicates a problem with the cruise control system, specifically related to the multi-function switch inputs. When this code is triggered, it signifies that the Powertrain Control Module (PCM) has detected a discrepancy between the voltage signals from the cruise control switch inputs A and B. This issue can lead to the malfunction of the cruise control system, affecting its reliability and functionality. Understanding this code is crucial for vehicle owners and DIY mechanics who wish to diagnose and repair their vehicles effectively.
P0585 Code Meaning | P0585 Code Common Causes |
---|---|
Cruise Control Multi-Function Input A/B Correlation | Defective multi-function switch |
Speed Control Switch 1/2 Correlation Error | Faulty cruise control module |
Malfunction in Cruise Control System | Open or shorted circuits in the wiring |
Inoperative Cruise Control System | Corrosion or poor connections in the switch circuit |
Symptoms of P0585 Code
When the P0585 code is present, vehicle owners may notice several symptoms:
- Inoperative Cruise Control: The cruise control system may fail to engage or operate as expected.
- Erratic Speedometer/Odometer Operation: Fluctuations in speed readings can occur, affecting overall driving experience.
- Flashing or Unresponsive Cruise Control Indicator: The indicator light may behave inconsistently, signaling issues within the system.
- Other Stored Codes: Additional trouble codes may be present, indicating related problems within the vehicle’s systems.
Technical Explanation
The P0585 code is categorized under powertrain codes and applies to various OBD-II compliant vehicles, including models from manufacturers like Dodge, Jeep, Chrysler, Ford, and Chevrolet. The PCM relies on inputs from the cruise control multi-function switch to manage the cruise control system. This switch controls multiple functions, including cruise control activation and other vehicle features.
The “A/B” designation refers to two separate input circuits that should provide correlating voltage signals. If these signals deviate from expected values, it triggers the P0585 code. The malfunction can stem from several factors, including defective switches, wiring issues, or faults within the PCM itself.
Step-by-Step Diagnosis of P0585 Code
Diagnosing a P0585 code involves a systematic approach to identify and rectify the underlying issue. Here’s how to proceed:
1. Gather Necessary Tools
Before beginning diagnostics, ensure you have the following tools:
- OBD-II scanner
- Digital Volt/Ohmmeter (DVOM)
- Vehicle-specific repair manual
- Basic hand tools for component access
2. Initial Inspection
Start with a visual inspection of the cruise control system:
- Check Wiring and Connectors: Look for any visible damage, loose connections, or corrosion on connectors leading to the multi-function switch and cruise control module.
3. Use an OBD-II Scanner
Connect your OBD-II scanner to retrieve any stored trouble codes:
- Review Freeze Frame Data: Analyze freeze frame data associated with the P0585 code for additional context regarding when it was triggered.
4. Clear Codes and Test Drive
Clear existing codes and take the vehicle for a test drive:
- Monitor for Reoccurrence: If the P0585 code returns after normal driving conditions, proceed with further diagnostics.
5. Voltage Testing
Using a DVOM, check voltage at the multi-function switch:
- Expected Voltage: Measure voltage levels while activating various functions of the cruise control switch.
- Ground Testing: Ensure that ground circuits are secure; if no voltage is detected, check fuses associated with the cruise control system.
6. Inspect Cruise Control Switches
Examine the condition of the cruise control switches:
- Functional Testing: Test each button on the multi-function switch for proper operation.
- Replace if Necessary: If switches are found defective or unresponsive, consider replacing them.
7. Check Cruise Control Module
Inspect and test the cruise control module:
- Visual Inspection: Look for signs of damage or corrosion.
- Functional Testing: If applicable, perform tests according to manufacturer specifications.
8. Reset System and Retest
After addressing any found issues:
- System Reset: Reset any stored codes and retest the cruise control functionality.
Solution Methods for P0585 Code
Addressing a P0585 code typically involves several potential solutions based on diagnostic findings:
- Replace Faulty Multi-Function Switch: If testing reveals that the multi-function switch is malfunctioning, replacement is necessary.
- Repair Wiring Issues: Fix any damaged wiring or poor connections identified during inspections.
- Replace Cruise Control Module: If all other components are functioning correctly but issues persist, consider replacing the cruise control module.
Cost Estimates for Repairs
Repair costs can vary widely based on labor rates and parts prices in different regions. Here’s a rough estimate:
- Multi-Function Switch Replacement: $100 – $300 (parts and labor)
- Cruise Control Module Replacement: $150 – $400 (parts and labor)
- Wiring Repairs: $50 – $150 depending on complexity
Warnings and Recommendations
While diagnosing and repairing a P0585 code can often be handled by DIY mechanics, there are important considerations:
- Professional Help Needed: If you are unsure about any steps or lack necessary tools, it’s advisable to seek help from a certified technician.
- Safety First: Always ensure that your vehicle is safely secured before working underneath it or accessing electrical components.
Closing Paragraph
The P0585 trouble code indicates issues within your vehicle’s cruise control system that can affect driving comfort and safety. By understanding its meaning, symptoms, causes, and diagnostic steps outlined above, vehicle owners and DIY mechanics can effectively troubleshoot and resolve this issue. Regular maintenance of electrical components can prevent future occurrences of this code and ensure reliable vehicle performance.
Frequently Asked Questions About P0585
- What does P0585 mean?
The P0585 code indicates a discrepancy between voltage inputs from the cruise control multi-function switch. - How serious is a P0585 code?
This code affects cruise control functionality but typically does not pose an immediate risk to vehicle operation. - Can I drive my car with a P0585 code?
While driving is permitted, it is advisable to repair this issue as soon as possible for optimal performance. - What tools do I need to diagnose P0585?
You will need an OBD-II scanner, DVOM, and basic hand tools for access. - How much does it cost to fix a P0585 code?
Repair costs can range from $50 to $400 depending on what needs replacing. - Can I fix this myself?
If you have basic automotive knowledge and tools, you may be able to diagnose and fix this issue yourself. - What should I do if my cruise control still doesn’t work after repairs?
If issues persist after repairs, further diagnostics by a professional technician may be necessary. - Are there other codes related to P0585?
Yes, other codes may indicate related issues within the cruise control system; checking all stored codes is recommended.