Cruise Control Servo Control Circuit High
The cruise control servo motor circuit is receiving too much voltage, like a speaker getting turned up too loud and distorting. The ECU detected excessive electrical current flowing through the cruise control actuator circuit.
The ECM monitors the voltage and current draw of the cruise control servo motor circuit. When the circuit voltage exceeds the normal operating range (typically above 14.5V or excessive current draw above 10-12A), the ECU flags a high voltage condition indicating a short or failed servo component.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Servo circuit voltage | 5-12V during operation | Above 14.5V or sustained high voltage |
| Servo motor current draw | 0.5-3A nominal | Above 10-12A or short detected |
Code P0596 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0596 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.