Conditions For Setting DTC P1860

WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

DTC sets when one of the following conditions exists for at least 5 seconds:

PCM commands solenoid to greater than 90 percent duty cycle and voltage feedback remains high (B+).
PCM commands solenoid to less than 10 percent duty cycle and voltage feedback remains low (zero volts).