Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Electronic Control Relay

electronic control relay

Bad or Failing Electronic Control Relay Inspection

by a top-rated mechanic at your home or office

The electronic control relay, also known as the “main” relay, is one of the various electronic relays found on modern vehicles. The electronic control relay is particularly important, as it is one of the main relays that feeds power to the computer, which controls a vast majority of the vehicle’s functions. As the electronic control relay powers the computer, when it fails it can cause all sorts of issues with the vehicle. Usually a bad or failing electronic control relay will produce a few symptoms that can alert the driver of a potential issue that should be serviced.

HAVE SYMPTOMS OF CAR TROUBLE?
Get an $80 diagnostic
by a top-rated mechanic at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

Engine cranks but does not start

One of the most common symptoms of a problem with the electronic control relay is an engine that cranks but does not start. If the relay has any sort of issue it may compromise power to the computer, which will not allow the vehicle to start. For many vehicles the engine’s starting circuit is on a separate circuit and relay than the computer’s, so the engine will still crank even if the computer relay has failed.

HAVE SYMPTOMS OF CAR TROUBLE?
Get your car fixed at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

Vehicle that powers on but does not function

Another symptom of a bad or failing electronic control relay is a vehicle that powers on when the key is inserted, but does not function. For some vehicles, the vast majority of the vehicle’s relays are powered by the computer, so any issue with the relay or computer may cause a problem with all of the electronic circuits on the vehicle powered through the computer. A vehicle with no power when the key is inserted will be rendered undriveable until the relay is replaced.

The electronic control relay is a critical relay to any vehicle, as it is what supplies power to the computer, one of the most important electronic components found on modern vehicles. When it fails, the functionality and driveability of the vehicle can be greatly affected. If you suspect that your electronic control relay may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic to determine if your car needs a relay replacement.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
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 Long Does a Throttle Return Spring Last?
Not all vehicles on the road feature an electronic throttle control (ETC), which is also called drive-by-wire. For vehicles that don't offer this system, they have a throttle cable instead that...
P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....


Related questions

Q: Battery light stays on and overnight battery drain. 2006 Land Rover LR3

Hi there - yes, something is going on here that's draining your battery. Perhaps the pressure of the engine wash dislodged wiring which has shorted, or there was a chemical reaction to the cleaning solution that caused electrical damage in...

Q: I have a 1994 Chevrolet c1500 red 5.7 v8. I replaced the alternator, battery, and starter. All I hear is a ding sound when I turn the key to the 'START' position.

Hi there. The starter needs shims to help clear the starter pinion gear to the ring gear on the flex plate. The starter pinion gear is hitting the ring gear and not sliding into the ring gear due to a...

Q: Car won't start, latching noise

If when turning the key you hear a loud click or latching noise, that may be the starter gear kicking out to contact the engine flywheel in an attempt to start. Test the battery while trying to start the vehicle....