Skip the auto shop - Our mechanics make house calls

P0502 OBD-II Trouble Code: Vehicle Speed Sensor Low Input

Check Engine Light

Vehicle Speed Sensor Low Input

What the P0502 code means

The P0502 trouble code means that the Engine Control Module (ECM) has detected a different reading of speed between the vehicle speed sensor and the wheel speed sensors.

What are the causes of the P0502 code?

  • A faulty vehicle speed sensor
  • Damaged wiring or connectors in the vehicle speed sensor circuit
  • Multiple faulty wheel speed sensors/ hub bearings
  • Broken ABS tone rings
  • A faulty powertrain control module
  • Incorrect size wheels or tires
  • A faulty instrument cluster

What are the symptoms of the P0502 code?

Other than a Check Engine Light and an inaccurate speedometer, there should be next to no symptoms associated with this trouble code.

How does a mechanic diagnose the P0502 code?

The most common cause of the P0502 trouble code is a faulty vehicle speed sensor so the mechanic would likely start by locating it. If the sensors wiring and connector seem to be in good condition, the mechanic would then test the vehicle speed sensor using the manufacturer’s recommended procedure.

The mechanic would also check all the wheels and tires to ensure they are the correct size. A check of the suspension on all four wheels would be performed to check the tone rings and wheel speed sensors.

Finally, if no other issues are found, the ECM would be tested and parts would be replaced at the customer’s request.

Common mistakes when diagnosing the P0502 code

A common mistake that could be made when this trouble code is stored would be to replace the vehicle’s instrument cluster due to the inaccurate speedometer. The instrument cluster receives a signal from the vehicle speed sensor so it is important to check there first.

How serious is the P0502 code?

This trouble code is not very serious at all due to the fact that it does not cause any drivability issues. The only thing to worry about with this trouble code is getting a speeding ticket due to the inaccurate speedometer.

What repairs can fix the P0502 code?

Repairs that can fix the P0502 trouble code may include:

Additional comments regarding the P0502 code?

Many people like the looks of very large wheels on their vehicle. However, they do not realize the potential damages this can cause to the vehicle. The ride quality suffers, the wheels are more susceptible to damage from pot-holes, the brakes do not work as well, the steering is not as predictable, and codes such as the P0502 may be stored.

Need help with a P0502 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

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
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...


Related questions

Q: No start

Hello. A no start condition can be caused by a wide variety of issues, and from what you describe it would appear that the vehicle may have more than one issue. If spraying brake cleaner into the intake helped...

Q: I have,a 2005 mercury montego it has a code p0320 and p2106 where should I start first cam or crank

Hello, thank you for writing in. Due to the codes that you have currently, you will want to start with the crankshaft position sensor. You can test it with a multi-meter or voltmeter if you are equipped. If may be...

Q: I installed a new crankshaft positioning sensor, now I'm getting misfires and code P0300. Is this supposed to happen?

Assuming you replaced your vehicle's crankshaft position sensor for a P0335 trouble code and that code has not returned, this leads me to believe that the new sensor is either faulty or misadjusted. The sensor replacement should not have caused...