P0580 OBD-II Trouble Code: Cruise control Multi-Function Input "A" Circuit Low

P0580 OBD-II Trouble Code: Cruise control Multi-Function Input "A" Circuit Low

Diagnostic Trouble Code (DTC): P0580

P0580 code definition

A P0580 code means that the PCM has found an electrical problem with the multi-function input circuit in the vehicle’s cruise control.

What the P0580 code means

In most vehicle models, the PCM works together with the cruise control module to automatically regulate the vehicle’s speed. If the PCM identifies that the speed cannot be automatically controlled, it initiates self-testing of the cruise control system. If the voltage/resistance level in the multi-function input circuit is abnormal, the PCM will record the P0580 code.

What causes the P0580 code?

Most likely, the cruise control switch has failed, or there are shorted or open circuits in the cruise control buttons due to spilled liquids. There could also be damaged wiring, corroded connectors, and/or blown fuses. In the case of blown fuses, though, this is generally due to a more serious problem in the system, not due to a fault with the fuse itself.

What are the symptoms of the P0580 code?

The Check Engine light may be illuminated, or it may not. In some vehicles, the PCM storing the P0580 code will not activate the Check Engine light, while in others, several drive cycles may need to occur before the Check Engine light comes on. There may also be a blown fuse, and it is unlikely that you will be able to make use of the vehicle’s cruise control. How does a mechanic diagnose the P0580 code? The first course of action is for the mechanic to use an OBD-II scanner and a digital volt/ohmmeter to diagnose the code. Then:

• Examine all the wires and connectors
• Replace or repair any faulty components and replace blown fuses
• Use the scanner to re- test, and record freeze frame data and stored codes
• Clear out the codes and run the vehicle
• If the codes do not come back right away, the problem may have been easily corrected, or could be intermittent
• If everything appears to be in proper working order but the codes are coming back, suspect a faulty cruise control switch
• Replace the switch, and take a test drive to see if the cruise control works
• If the problem is not fixed, raise the drive wheels, ensure that the vehicle is secured, and get an assistant inside the vehicle in order to get the speedometer up to the point where the cruise control can be activated
• Use the digital volt/ohmmeter to check the voltage, with the cruise control switch’s electrical connector disconnected
• See if the findings are compliant with the vehicle manufacturer’s specifications, and if they are, disconnect both the PCM and the cruise control module, and check the circuitry in the PCM, passenger cabin switches, and fuse panel
• Compare the findings again, and repair any open or shorted circuits
• Again, clear the codes and do a re-test
• If no abnormalities are identified, do a resistance test on the on/off switch and the cruise control buttons, with the PCM and the cruise control disconnected
• Replace the cruise control switch
• Clear codes, and re-test

Common mistakes when diagnosing the P0580 code

Mechanics will sometimes assume that the problem is with faulty components without considering that the issue could just be a blown fuse. Most of the time, though, when a fuse blows, it is due to a fault elsewhere in the system.

How serious is the P0580 code?

Some drivers never use their vehicle’s cruise control. Others don’t miss it all that much if they do lose it. An inability to use the vehicle’s cruise control is not going to endanger you, your passengers, or anyone else on the road, so you can take your time getting the issue fixed, if you choose to have it fixed at all.

What repairs can fix the P0580 code?

There are a number of things a mechanic can do to fix the P0565 code, including:

• Replace blown fuses
• Replace or repair damaged wiring and connectors
• Replace the cruise control switch
• Replace the PCM (although usually the PCM itself will not fail)

Need help with a P0580 code?

Whenever you need vehicle repairs, you can rely on YourMechanic to dispatch a qualified mechanic to your home or workplace. Call us at 1-800-701-6230, use our convenient online form to arrange an appointment.