Cruise Control Input Circuit High
The P0577 code indicates that the powertrain control module (PCM) has detected a high voltage signal from the cruise control input circuit. This typically occurs when the brake switch or cruise control switch is stuck closed or shorted to power, causing the PCM to see a constant high signal. The circuit may also be damaged or corroded, leading to incorrect voltage readings.
01. Most Common Causes
- Faulty brake switch (stuck closed or shorted)
- Faulty cruise control switch
- Short to voltage in the cruise control input circuit
- Corroded or damaged wiring/connectors
02. Symptoms You Will Notice
- Cruise control inoperative
- Cruise control light on dash illuminated
- Brake lights may stay on or not work properly
- Check Engine Light on
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Inspect the brake switch for proper operation and adjustment.
Step 3: Check the cruise control switch and wiring for shorts or opens.
Step 4: Test the voltage at the cruise control input circuit with a multimeter.
Step 5: Repair or replace any faulty components and clear codes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive, but cruise control will not work. If the brake lights are affected, it may be unsafe.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the cause.