What is the difference between a pending code and a stored code?
How the computer decides
When the car detects a problem, it often saves a pending code first. If the same fault shows up again on later drive cycles, the code becomes confirmed and the check engine light may come on. Some faults are not confirmed until several trips.
This is why a pending code can appear before a warning light. It is an early warning, and the car may clear it on its own if the problem goes away. Still, it is worth checking if the same code keeps coming back.
- Pending means seen but not confirmed yet
- Confirmed codes often turn on the warning light
- Some codes need several drive cycles
- Recurring pending codes deserve a look
What to do with each
Read both pending and confirmed codes when you scan the car. Note the code and whether it stays after driving. A pending code that never returns may not need a repair, but keep an eye on it.
Clearing codes does not fix the root cause. The code may return as soon as the fault happens again, so use the code as a clue for testing.
- Read pending and confirmed codes
- Record codes and when they appear
- Test the cause instead of clearing codes
Common mistakes
- Ignoring a pending code that keeps returning on each drive.
- Clearing codes and assuming the car has been fixed.
- Confusing a pending code with a light that is already on.
