What causes a SPN 2111 code?

SPN 2111 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 2111 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2111 active.

How do I fix SPN 2111?

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

Log in Sign up

J1939 SPN

SPN 2111

Transmission Gear Ratio Error - 1st Gear

What it means

Detected mismatch between input and output speed while in first gear, indicating mechanical slip.

Sign in to view symptoms, probable causes, diagnostic steps, severity, and related codes

Log in Sign up free