Technical Description of OBD-II Trouble Code
The control circuit for Cooling Fan 3 is experiencing low voltage
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) that applies to all vehicles manufactured from 1996 onwards. The specific steps for repairing this issue may vary depending on the make and model of the vehicle.
The electric motors used to operate the fans that cool the engine’s radiator are controlled by the powertrain control module (PCM), which receives input from the engine coolant temperature sensor (ECT). When the ECT reaches a certain temperature, the PCM activates the fans. Once the ECT cools to a predetermined temperature, the PCM turns the fans off.
The PCM controls the cooling fans by sending a ground signal to the cooling fan relay. When the fans are not activated, the voltage on the signal circuit is high, close to the battery voltage. Conversely, when the fans are activated, the voltage is close to zero. DTC P0695 is triggered when the PCM detects a low voltage when the cooling fan 3 is not activated.
Symptoms & Severity of Code
Symptoms of a P0695 code may include:
If the cooling fans are not functioning properly, there is a high likelihood of the engine overheating. Therefore, caution should be exercised when driving the vehicle under conditions that could trigger this DTC. It is recommended to have the issue repaired as soon as possible.
Causes
Possible causes for this code to be triggered are:
Diagnostic and Repair Procedures
In my experience, a blown cooling fan fuse is the most common cause of this DTC. Checking the fuse is as simple as locating it, removing it, and visually inspecting it. Usually, you can determine if a fuse is good or not through visual inspection. If the fuse is indeed blown, try replacing it with the correct amperage fuse. If the fuse blows again, the next question to consider is when it blew.
If the fuse failed immediately after replacement, there may be a direct short circuit between the fuse and the relay. If it failed when the engine reached operating temperature, the most likely cause is a frozen cooling fan motor. With the engine and ignition key off, try to manually spin the fan blades. They should rotate freely. If they do not, the fan motor is frozen and needs to be replaced. If the fuse is intact, the problem is likely with the cooling fan relay. If replacing the relay does not resolve the issue, a faulty PCM may be suspected.
Exercise caution when working around components that are not only hot but also in motion.
