What causes a SPN 520970 code?

SPN 520970 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 520970 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 520970 active.

How do I fix SPN 520970?

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 520970

Transmission Output Speed Sensor

What it means

This code signifies an issue with the transmission output speed sensor, indicating an implausible or missing signal. This sensor is crucial for shift timing and vehicle speed calculation.