Cruise Control Multi-Function Input "A" Circuit
P0564 indicates a problem with the cruise control multifunction input circuit (Input A), which is the electrical pathway that receives signals from the cruise control switches. This code sets when the PCM detects an abnormal voltage or signal pattern from the cruise control input switch assembly, preventing the cruise control system from operating properly.
What You Might Notice
- Cruise control does not engage or is inoperative
- Cruise control light remains illuminated even with switch off
- Vehicle speed fluctuates abnormally when cruise control is active
- Unable to set or maintain desired cruise control speed
- Cruise control switches unresponsive to driver input
Most Common Causes
- 1
Faulty cruise control switch
The multifunction cruise control switch on the steering wheel or stalk has failed electrically or mechanically. This is the most common cause and typically requires switch replacement.
- 2
Wiring harness damage or corrosion
The electrical wiring connecting the cruise control switch to the PCM has corroded, shorted, or developed an open circuit. Moisture or poor connections are frequent culprits.
- 3
PCM or module connector issue
The connector at the powertrain control module or related control module has become loose, corroded, or damaged, disrupting signal transmission from the input circuit.
- 4
Steering wheel clock spring failure
The clock spring assembly that allows electrical signals to pass through the rotating steering wheel has failed, interrupting the cruise control input signal pathway.
How to Diagnose It
- 1
Check Faulty cruise control switch — The multifunction cruise control switch on the steering wheel or stalk has failed electrically or mechanically. This is the most common cause and typically requires switch replacement.
- 2
Check Wiring harness damage or corrosion — The electrical wiring connecting the cruise control switch to the PCM has corroded, shorted, or developed an open circuit. Moisture or poor connections are frequent culprits.
- 3
Check PCM or module connector issue — The connector at the powertrain control module or related control module has become loose, corroded, or damaged, disrupting signal transmission from the input circuit.
- 4
Check Steering wheel clock spring failure — The clock spring assembly that allows electrical signals to pass through the rotating steering wheel has failed, interrupting the cruise control input signal pathway.
How to Fix It
- 1
Replace cruise control switch
Remove the steering wheel or access the cruise control switch assembly and replace the faulty multifunction input switch. This resolves the majority of P0564 codes.
- 2
Inspect and repair wiring harness
Locate the wiring harness between the cruise control switch and PCM, inspect for corrosion, damage, or loose connections. Repair, replace, or reposition damaged sections as needed.
- 3
Clean or replace PCM connectors
Disconnect and inspect the powertrain control module connectors for corrosion, pin damage, or loose terminals. Clean with electrical contact cleaner or replace connectors if damaged.
- 4
Replace steering wheel clock spring
If the clock spring is confirmed faulty, remove the steering wheel and replace the clock spring assembly to restore the cruise control input signal path.
Need a deeper diagnosis?
Search for related repair guides or browse by system.