Technical Description of OBD-II Trouble Code
The control circuit for Cooling Fan 1 Relay is experiencing high voltage.
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) that is applicable to most vehicles manufactured from 1996 onwards. The specific repair steps may vary depending on the make and model of the vehicle.
The electric motors used to cool the engine’s radiator are responsible for running the fans. The powertrain control module (PCM) turns these motors on and off based on readings from the engine coolant temperature sensor (ECT). In other words, when the ECT reaches a predetermined temperature, the PCM activates the fans. Then, when the ECT cools down to a predetermined temperature, the PCM deactivates the fans.
The PCM controls the cooling fans by sending a ground signal to the cooling fan relay. When the fans are not commanded on (not grounded), the voltage on the signal circuit is high, approximately equal to the battery voltage. Conversely, when the fans are commanded on (grounded), the voltage is close to zero. DTC P0692 is triggered when the PCM detects that the voltage remains high even when the cooling fans are commanded on.
Symptoms & Severity of Code
The symptoms of a P0692 code may include:
If the conditions required to trigger this DTC are present, there is a high likelihood that the engine may overheat due to non-operational cooling fans. Therefore, caution should be exercised when driving the vehicle under such conditions, and the issue should be repaired as soon as possible.
Causes
The potential causes for this code to be triggered are:
Diagnostic and Repair Procedures
In my experience, a faulty cooling fan relay is the most common cause of this DTC. One simple way to check the relay is to locate it and visually inspect for other identical relays. Then, switch the two relays and clear the codes. Run the vehicle and if the code does not reappear, replace the relay. If the code does reappear, suspect a possible issue with the PCM.
Note: It is crucial to ensure that the relay being switched is identical in every way. Installing an incorrect relay could cause damage to the PCM. Nissan, in particular, has relays that may appear similar but have slight differences in color and will damage the PCM if plugged into the same socket.
