What causes a P1023 code?

P1023 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 P1023 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1023 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

P1023

BPV CAN sensor temperature too high

What it means

The Bypass Valve (BPV) CAN-linked control unit has reported an internal temperature sensor value that exceeds the safe operating threshold.