What causes a P1201 code?

P1201 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 P1201 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1201 active.

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

OBD-II

P1201

Cylinder 1: Injector needle valve open circuit

What it means

The ECM has detected an interrupted electrical path (open circuit) to the #1 fuel injector solenoid, meaning the injector cannot be energized to spray fuel.