P0691 Cooling Fan 1 Control Circuit Low. Dtc p0691 is set when the pcm senses the voltage low when the cooling fan 1 is off. This code is a generic trouble code meaning it applies to all vehicles equipped with the obd ii system especially those made since 1996 up to present.
The engine control module ecm grounds the low speed relay which is the fan low relay and the high speed relay which is the fan high relay control circuits through an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. The level can be too high or too low.
The primary function of the driver is to supply the ground for the component being controlled.
Specifications on the description diagnosis and repairs of course may vary from one make and model to another. Symptoms of a p0691 code may include. This code is a generic trouble code meaning it applies to all vehicles equipped with the obd ii system especially those made since 1996 up to present. Check engine light on.
