Cruise Control Multi-Function Input Circuit Stuck
The P0590 code indicates that the Powertrain Control Module (PCM) has detected a stuck signal from the cruise control multi-function input circuit. This circuit typically includes inputs from the steering wheel switches (set, resume, cancel, etc.) and the brake pedal position sensor. When the signal remains in a fixed state (e.g., always high or low) for an extended period, the PCM sets this code. Common causes include a faulty cruise control switch, wiring issues, or a malfunctioning brake switch. This can prevent the cruise control from engaging or cause it to disengage unexpectedly.
01. Most Common Causes
- Faulty cruise control multi-function switch
- Short or open in the cruise control circuit wiring
- Malfunctioning brake pedal position sensor or switch
- Corroded or loose electrical connectors
02. Symptoms You Will Notice
- Cruise control inoperative or intermittent operation
- Cruise control disengages unexpectedly
- Cruise control cannot be set or resumed
- Check Engine Light illuminated
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the cruise control switch and wiring for damage or corrosion.
Step 3: Test the cruise control switch continuity with a multimeter.
Step 4: Check the brake pedal position sensor and switch operation.
Step 5: Clear the code and test drive to see if it returns.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but the cruise control will not function properly. The vehicle's braking and acceleration are unaffected.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the root cause and labor rates.