What causes a P249C code?

P249C can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P249C code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P249C active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

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OBD-II

P249C

Time To Enter Closed Loop Reductant Injection Catalyst Warmup Too Long

What it means

The exhaust system is taking too long to reach the temperature required to start DEF dosing.

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