Variable Cam Timing Overadvanced (Bank #1)/ Misfire Detected - No Communication with BCM
Your engine's timing is advancing too much on one side, causing misfires and losing communication with the body control module. Think of it like a musician playing ahead of the beat—everything falls out of sync.
The ECM monitors camshaft position timing relative to crankshaft position using the cam timing sensor. It compares actual cam advance against commanded values and detects misfires via oxygen sensors and ignition timing variance. A fault occurs when cam timing exceeds calibrated limits and misfire thresholds are crossed simultaneously.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Cam Advance Angle (Bank #1) | Within ±5 degrees of target | Greater than +8-10 degrees overadvanced |
| Misfire Count | 0-2 per 1000 revolutions | Greater than 5 per 1000 revolutions |
Code P1386 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, P1386 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.