Cruise Control Multi-Function Input Correlation Failure
The P0585 code indicates that the Powertrain Control Module (PCM) has detected a correlation error between the cruise control multi-function input signals. This typically means the signals from the steering wheel controls (e.g., SET, RESUME, CANCEL) do not match the expected pattern, often due to a faulty switch, wiring issue, or a problem with the clock spring. The system may disable cruise control to prevent unintended acceleration.
1. Most Common Causes
- Faulty cruise control switch on steering wheel
- Damaged clock spring (spiral cable) in steering column
- Corroded or loose wiring/connectors in cruise control circuit
- Malfunctioning PCM (rare)
2. Symptoms You Will Notice
- Cruise control inoperative or intermittent
- Check Engine Light illuminated
- Cruise control indicator on dash may flash or stay off
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0585 and check for other related codes.
Step 2: Visually inspect the cruise control switch and clock spring for damage or wear.
Step 3: Test the switch and clock spring continuity with a multimeter per manufacturer specs.
Step 4: Check wiring and connectors for corrosion, looseness, or shorts.
Step 5: If all else passes, update PCM software or replace PCM as last resort.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but cruise control will be disabled. The vehicle will operate normally otherwise.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and switch replacement. Clock spring replacement may cost $200-$400.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.