CAT 3406E (Prefix 1MM or 2WS) Fault Code: 56 PID: SPN: 253 FMI: 2 Check Customer or System Parameters

Conditions Which Generate This Code:

This condition indicates a customer specified parameter or a system configuration parameter that requires programming has not been programmed.

Probable Causes:

1) New ECM on vehicle, needs to be programmed
2) Current ECM programmed incorrectly
3) ECM Connection/harness

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