What causes a SPN 64 code?

SPN 64 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 64 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 64 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.

OBDIY

J1939 SPN

SPN 64

J1939 SPN 64 — Engine parameter

What it means

SPN 64 typically refers to Engine Speed (Secondary) or Camshaft Speed. This sensor monitors the rotational speed/position of the engine to sync timing for fuel injection.