What causes a SPN 1870 code?

SPN 1870 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 1870 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1870 active.

How do I fix SPN 1870?

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 1870

SPN 1870 Brake Actuator Position Signal High

What it means

Indicates the electronic braking system (EBS) or ABS controller has detected a voltage or frequency signal from the brake actuator that is above the normal operating range.