Misfire Detected - Rough Road Data Not Available
Your engine is misfiring (cylinders not firing properly), but the system can't use rough road data to confirm it's a real problem versus normal bumps. Think of it like trying to hear a knock in your door while someone's shaking the whole house.
The ECM monitors crankshaft acceleration variations to detect misfires using rough road detection, which filters out vibrations from road conditions. When rough road data is unavailable, the system flags borderline misfire signals that may be false triggers caused by suspension movement rather than actual combustion failure.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Crankshaft Acceleration Variation | Within expected RPM fluctuation band | Exceeds threshold without rough road confirmation |
| Rough Road Data Status | Data available and filtering active | Data unavailable; filtering disabled |
Code P1385 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, P1385 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.