What causes a P1870 code?

P1870 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 P1870 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1870 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

P1870

Crankcase ventilation pressure sensor out of range low

What it means

The Engine Control Module (ECM) detects that the Crankcase Pressure Sensor signal is lower than the minimum allowable voltage for current operating conditions.