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P0493 is a diagnostic trouble code (DTC) for "Fan Overspeed". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
A P0493 trouble code is related to a vehicle’s electric cooling fan, or auxiliary fan, that helps the radiator maintain engine coolant temperatures that are within the manufacturer’s parameters. Typically, this fan is also triggered by a vehicle’s HVAC system.
P0493 is an OBD-II generic code for a voltage problem with the electric cooling fan control system in that the signal being sent to the engine computer is incorrect. This either means there is a bad ground or the fan isn’t working.
There could be a variety of causes for a P0493, but the most common culprits are:
Other than A Check Engine Light, there shouldn’t be any severely adverse driving conditions caused by a P0493. However, because the electric cooling fan is used to keep coolant temperatures below an overheating threshold, you may find your vehicle running hotter than normal in conditions such as stop-and-go traffic. The fan is also used frequently to accelerate and maintain cooling of the air conditioning, which may be diminished if the fan is inoperable.
Your mechanic will start at the easiest first - giving a visual inspection of the fan, its wiring and electrical connectors, associated fuses and the control relay. If nothing looks to need repairs, they will then trigger the fan to power by either jumping the relay, sending 12 volts directly to the fan, or triggering it via the air conditioning. If and under what conditions the fan turns on will help determine the route cause of the problem.
For example, if the fan turns on when the relay is jumped but does not when the air conditioning is triggered, chances are high the relay is bad. If the fan doesn’t turn on at all, the motor is bad and will need to be replaced. The key with a P0493 is first confirming if the fan motor is good and then moving on to the next most common cause, typically the relay.
Rushing to replace parts like the fan and the relay can become costly, so it really pays to test each component of the vehicle’s electric cooling system.
A P0493 shouldn’t cause serious issues but if you have a code, you’ll want to be on high alert in slow driving conditions with high ambient temperatures. While it’s unlikely that a vehicle will overheat severely without an electric cooling fan, a hot-running engine will not perform as well as normal.
The most common repairs for a P0493 are as follows:
If you’re dealing with a P0493 on a used vehicle with unknown history, you’ll want to also make sure you’re not dealing with someone else’s shadetree work. Having personally triggered this code by modifying a vehicle’s factory fan to a toggle switch, it can take a lot of research and soldering to make sure it goes away with a modification.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.