Code result
P21C1
Cold Start Cylinder 12 Injection Timing
Moderate severity
What it means
Cylinder 12 cold-start injection timing is outside the calibrated window. Diesel cold-start uses adapted injection timing per cylinder to limit white smoke and noise; deviation typically points at a worn injector or faulty crank/cam correlation.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Injector flow-rate aged
highOne of the most commonly reported causes for this code — check this first.
Related help
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