KEY TAKEAWAYS
  • 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.
01

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.

02

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.

03

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.

04

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.
COMMON QUESTIONS
Is a pending code less important?

It is less confirmed, not necessarily less serious. Pair it with symptoms, freeze-frame conditions, and repeat observations.

How do you reset a permanent OBD-II code?

A scan tool or battery disconnect should not erase a permanent emissions code. Confirm the repair, then let the vehicle complete the applicable monitor so the onboard system can verify the fault is gone.

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.

CHECK WHAT YOUR SETUP CAN READ

Turn the warning into a saved record.

Use ScanWrench to capture the standardized evidence your exact vehicle and compatible adapter return. Manufacturer-controlled systems remain not checked unless exact support is verified.

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HOW TO USE THIS GUIDE

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.

AUTHORSHIP · SOURCES · CORRECTIONS

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These links are primary-source starting points for the page's scope. They do not replace the current manufacturer procedure, wiring, specification, or service information for a specific vehicle.

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ScanWrench Editorial is the working byline for this library. Joshua Black, founder and publisher, is responsible for publication decisions, disclosures, and corrections.

A reviewed date means an editorial scope and safety check. It is not an ASE credential, OEM authorization, or vehicle-specific repair approval.

Primary sources

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  1. Reviewed edition: claim boundaries, safety language, internal links, and cited source scope checked.

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