221
UnclassifiedGeneral
What This Code Means
WEAK BATTERY warning displayed; Genset battery voltage below threshold during engine cranking
Possible Causes
- •Battery voltage is below the weak battery threshold during cranking
- •Genset battery voltage is below battery thresholds during cranking
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Get a diagnosis walkthrough for 221 on your specific Cummins unit — cited to the OEM manual, not a forum guess.
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