- Pending means observed, not imaginary.
- Stored means the controller’s confirmation criteria were met.
- Permanent codes clear only after the onboard system verifies the repair.
- Always capture status before clearing codes or disconnecting power.
Pending codes
Pending codes are early observations from supported emissions monitors. Some mature into stored codes after another failure; others disappear after enough passing tests. They are especially valuable for intermittent complaints because they can reveal a developing condition before the malfunction indicator lamp turns on.
Stored or confirmed codes
A stored code has satisfied the module’s confirmation logic. That may require one severe failure, failures on consecutive trips, or a manufacturer-defined pattern. A stored code is stronger evidence that a monitored condition occurred, but it still does not prove a specific component failed.
Permanent codes
Permanent emissions codes are designed to resist simple clearing. A scan command or battery disconnect should not erase them. The vehicle removes them after its own monitor reruns and confirms that the fault is no longer present. This makes drive-cycle conditions and readiness progress part of repair verification.
A disciplined sequence
Save all channels, the malfunction indicator status, readiness, freeze frames, and timestamps. Diagnose and repair. Then compare the post-repair record under similar conditions. A permanent code that remains while its monitor has not run is different from one that remains after a completed monitor fails again.
- Before repair: preserve all evidence.
- After repair: check current and pending channels.
- After the required monitor runs: confirm readiness and permanent-code state.
Is a pending code less important?
It is less confirmed, not necessarily less serious. Pair it with symptoms, freeze-frame conditions, and repeat observations.
Why did a permanent code stay after the repair?
The relevant monitor may not have completed yet. Confirm the repair, then allow the vehicle to run its specified verification cycle.
This is general educational material designed to improve questions and evidence capture. Definitions, thresholds, enabling conditions, wiring, service steps, and safety requirements can differ by vehicle application. Use current official manufacturer information and qualified judgment for the actual repair.