Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P0494 OBD-II Trouble Code: Fan Speed Low

P0494 OBD-II Trouble Code: Fan Speed Low

Check Engine Light

Diagnostic Trouble Code (DTC): P0494

P0494 code definition

If the PCM has detected a voltage reading that is too low from the electric cooling fan control circuit, the P0494 code will be stored.

What the P0494 code means

The P0494 code relates to the engine cooling and air conditioner systems. In order ensure that the engine temperature remains at the right level, and that the air conditioner is operating correctly, the PCM gathers data from the circuitry in the cooling fan control system. If this data is more than 10% lower than the voltage specified by the manufacturer for the current driving conditions, then the PCM will store the P0494 code.

What causes the P0494 code?

Most of the time, a bad cooling fan motor, or a faulty cooling fan relay, are to blame for this code. However, there are some less-common causes that should be considered, such as:

What are the symptoms of the P0494 code?

In most cases, the illuminated Check Engine Light will be the only observable symptom. Some vehicles may overheat, and the air conditioner may not work as efficiently.

How does a mechanic diagnose the P0494 code?

After verifying the code with an OBD-II scanner, the mechanic should begin with a visual inspection of all wiring and other electrical components, as well as vacuum lines and hoses. Any simple electrical issues, such as loose or shorted elements, should be repaired.

After this, or any, repair, it is important to clear the code and retest the system. If the code returns, then the mechanic must continue by checking the voltage of the primary cooling fan motor. The next step is to check the voltage readings of the engine cooling fan relay. If either of these parts are not meeting the manufacturer’s specifications, they must be replaced.

The mechanic should continue in this manner, diagnosing and retesting the system after each possible diagnosis, until the cause is found.

Common mistakes when diagnosing the P0494 code

The most common mistake when diagnosing and repairing this code is to replace a cooling fan motor without performing a thorough diagnostic procedure of the entire system. For example, cooling fan relays are frequently recalled, and may therefore be the true issue. It is important to diagnose all possible problems before replacing any major parts.

How serious is the P0494 code?

If the P0494 code is stored in the PCM, it represents a serious issue that should be repaired immediately. Although no major symptoms are usually observed, the inability to measure and control the cooling system will eventually lead to larger and more expensive repairs. It is important to have this issue fixed as soon as the code is detected.

What repairs can fix the P0494 code?

There are a few ways that a technician can address a P0494 code detection. They include:

Need help with a P0494 code?

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...


Related questions

Q: Random misfire cylinder 123

I'm curious as to what codes are still active. Is it still a misfire code? Several other component failures can cause "misfire" issues - a clogged exhaust gas recirculation valve, a failed diverter valve, even a failed cam phaser. But...

Q: VEHICLE ISSUES

German luxury cars built in this century are very complicated. They have multiple electronic control units for different functions, one for the engine, one for the transmission, one for the brakes and half a dozen more for various body functions....

Q: I was driving and sudenly i noticed car is stopping so i pulled over and noticed the radiator cap came out

If the vehicle overheated, that alone can cause a no start condition due to fuel vapor lock. If, once the vehicle has cooled down, it still won't start, that can be resolved if you request a no start diagnostic. The...