What causes a SPN 4205 code?

SPN 4205 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 4205 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 4205 active.

How do I fix SPN 4205?

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 4205

Allison transmission code P4205

What it means

Retarder Accumulator Solenoid Control Circuit - Signal circuit is open or shorted.

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

Log in Sign up free