P016A
Excessive Time To Enter Closed Loop Air/Fuel Ratio Control
ECU took longer than allowed to enter closed-loop air/fuel ratio control. Most often O2 sensor heater aging or coolant temperature reading wrong.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- O2 sensor heater agedCommon
Parts involved
- Oxygen Sensor
- ECT Sensor
P016A is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.