What causes a SPN 4627 code?

SPN 4627 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 SPN 4627 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 4627 active.

How do I fix SPN 4627?

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.

OBDIY

J1939 SPN

SPN 4627

Cummins fault code 4627

What it means

ECM Power Relay Control Circuit - Voltage Below Normal or Shorted to Low Source. This fault occurs when the ECM detects that the power supply to the ECM has dropped below a calibrated threshold or the relay control circuit is malfunctioning.