Not assigned in the generic OBD-II standard - if your scan tool shows this code, it is manufacturer-specific; verify the meaning in your make's service information
The P2921 code means the vehicle's onboard diagnostic system has detected: Not assigned in the generic OBD-II standard - if your scan tool shows this code, it is manufacturer-specific; verify the meaning in your make's service information. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- Unknown until the make-specific meaning is confirmed
Common Symptoms
- Depends entirely on the manufacturer-specific meaning - no generic definition exists
Probable Causes (Ranked by Likelihood)
- This code ID is not assigned in the generic OBD-II standard; a stored instance is manufacturer-defined High
Step-by-Step Diagnostic Procedure
-
Confirm the code with a make-specific (enhanced) scan tool - generic readers may misreport it.
-
Look the code up in your manufacturer's official service information; generic OBD-II references do not define it.
Frequently Asked Questions
Why can't I find a standard definition for P2921?
Because the generic OBD-II standard does not assign this ID. Any stored P2921 is a manufacturer-specific code, and its meaning must come from your make's service documentation. Sites that show a confident generic definition for it are generating one automatically.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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