The coolant pump is usually located near the engine, either on top of the engine or at the front of the engine. This pump is operated through an electrical signal provided by the PCM (Powertrain Control Module), which, based on the input data, determines the time and amount of time required for the pump to operate. It should be noted that the pump running time depends on the temperature of the intake air, the engine coolant, the air conditioning system, and the engine rpm.
If the PCM detects that the “B” coolant pump has experienced a performance problem in its control circuit, the P261B OBDII fault code will be set.