Speed Control Command Switch Out of Range Low
Your cruise control switch is sending a weak electrical signal to the engine computer, like a dimming light switch that's not making proper contact. The ECU can't read the command clearly and shuts down the cruise control system for safety.
The ECM monitors the voltage signal from the cruise control command switch. When you press buttons on the steering wheel or stalk, it should send a specific voltage range. A low voltage reading below the minimum threshold triggers this fault, indicating a poor connection or failing switch.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Cruise Control Switch Voltage | 0.5V - 4.5V (varies by position/button) | Below 0.2V (open circuit or low signal) |
| Switch Signal Detection | Readable and stable signal | Intermittent or missing signal |
Code P1573 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, P1573 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.