The P0594: Cruise Control Servo Control Circuit/Open refers to an issue in the cruise control system where the servo control circuit is either open or malfunctioning. This can be caused by a faulty servo control circuit, an open circuit, or wiring issues, leading to improper or non-functional cruise control operation.
P0594 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0594: Cruise Control Servo Control Circuit/Open |
| Is it serious? | No, but it can prevent the cruise control from functioning properly. |
| Possible causes | – Faulty servo control circuit – Open circuit or wiring issue – Faulty cruise control module |
| How to diagnose? | – Test servo control circuit – Inspect wiring and connectors – Test cruise control module |
P0594 Meaning
The P0594 code indicates that the cruise control system has detected an open or faulty servo control circuit. This could be due to a malfunction in the circuit, wiring problems, or an open circuit. The issue may cause the cruise control system to stop functioning or operate incorrectly.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for any additional codes related to the cruise control system. | OBD-II Scanner |
| Test the Servo Control Circuit | Use a multimeter to test the servo control circuit for continuity and proper operation. | Multimeter |
| Inspect Wiring and Connectors | Inspect the wiring and connectors for damage, disconnections, or corrosion. | Flashlight, Multimeter |
| Test the Cruise Control Module | Verify that the cruise control module is functioning correctly and handling the servo circuit properly. | Diagnostic Tool, Multimeter |
| Clear the Code and Test | After repairs, clear the code using an OBD-II scanner and test the cruise control system to confirm that it works properly. | OBD-II Scanner, Vehicle Manual |
Free PDF: How to choose OBD2 scanner
I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.
Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)