Crankshaft Position (CKP)/Ignition Coil - Cylinder 4 - Early Activation Fault
The ignition coil for cylinder 4 is firing too early compared to when the crankshaft sensor says it should. Think of it like a sprinter leaving the starting block before the gun goes off.
The ECM monitors the timing relationship between the crankshaft position sensor signal and the ignition coil activation for cylinder 4. It expects the coil to fire within a specific window relative to crankshaft position. Early activation means the coil is triggering before the ECM's calculated ignition timing, indicating a wiring, sensor, or coil driver issue.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Coil activation timing vs CKP signal | Within ±2-5° crankshaft angle of calculated spark timing | Coil fires >5° ahead of expected ignition point |
| CKP signal continuity | Stable sensor voltage transitions | Erratic or missing CKP teeth causing premature coil trigger |
Code P1382 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, P1382 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.