P0579 Fault Code

Cruise Control Multi-Function Input A Circuit Range/Performance

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0579 code indicates that there is an issue with the Cruise Control Multi-Function Input A Circuit, which is responsible for the operation of the cruise control system in your vehicle. This code points to performance or range problems within this circuit that could affect your ability to use cruise control effectively.

• Importance of the cruise control system in maintaining speed and improving fuel efficiency.
• Relation of the multi-function input circuit to other components in the cruise control system.

What are the symptoms of the P0579 code?

Common symptoms associated with the P0579 code may include:

• Cruise control not engaging or disengaging unexpectedly.
• Inability to maintain set speed.
• Illuminated check engine light.
• Erratic behavior of the throttle response while cruise control is active.

What causes the P0579 code?

The causes of the P0579 fault code may include:

• Faulty brake pedal switch.
• Malfunctioning cruise control switch.
• Wiring issues such as shorts or opens in the circuit.
• Corrosion or poor connection in electrical connectors.
• Faulty engine control module (ECM).

How to fix P0579?

To address the P0579 code, consider the following steps:

• Inspect the brake pedal switch and ensure it is functioning properly.
• Check the wiring and connectors for any signs of damage or corrosion.
• Test the cruise control switch for proper operation; replace if faulty.
• Use a multimeter to check for continuity in the circuit.
• If all components seem fine, a professional diagnostic may be needed to check the ECM.