Injector Circuit Open / Shorted - Cylinder #1
The fuel injector for cylinder #1 has an electrical problem—either it's not receiving power or the wiring is shorted. Think of it like a light switch that's broken and won't turn the light on or off properly.
The ECM monitors injector circuit voltage and current during each fuel injection pulse. It expects to see a specific voltage rise when the injector coil energizes and a controlled current draw during the pulse duration. If voltage doesn't rise or current stays at zero, the ECM detects an open circuit; if current exceeds safe limits, it detects a short.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Injector Circuit Current | 2-4 amps during pulse | 0 amps (open) or >6 amps (short) |
| Circuit Voltage Response | 12V drop during activation | No voltage change detected |
Code P1206 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, P1206 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.