What causes a SPN 520207 code?

SPN 520207 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 520207 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 520207 active.

How do I fix SPN 520207?

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 520207

SCR Inlet Temperature

What it means

Indicates an issue with the Selective Catalytic Reduction (SCR) inlet temperature sensor, which monitors exhaust gas temperature entering the SCR system. Essential for proper DEF dosing.