What causes a SPN 4207 code?

SPN 4207 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 4207 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 4207 active.

How do I fix SPN 4207?

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 4207

Allison transmission code P4207

What it means

C1/C2 Solenoid Circuit Low. Indicates the TCM has detected a low voltage/low current condition in the C1 or C2 clutch solenoid circuits, suggesting a short to ground or an open circuit.