What causes a SPN 1120 code?

SPN 1120 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 1120 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1120 active.

How do I fix SPN 1120?

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 1120

Clutch Pedal Position Sensor Supply Voltage

What it means

Generic J1939 parameter for a voltage fault in the supply to the clutch position sensor circuit.

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

Log in Sign up free