What causes P1870?
What causes P1870? The GM transmission fault code P1870 is particularly serious, because it typically indicates functionality problem. When the vehicle exceeds acceptable RPM parameters before a shift occurs, this transmission DTC will be set. What's the history code for DTC p1870? ......DTC P1870 is a type B code. The conditions for setting the P1870 DTC must occur on TWO CONSECUTIVE TRIPS (ignition cycles, with a drive cycle) before setting a P1870 history code. ......When the conditions for setting DTC P1870 are met (first trip), the PCM commands maximum line pressure and harsh 1-2 shifts are the result. What causes...