Symptoms of a Bad or Failing ECM-Power Relay

Our certified mechanics come to you · 12-month, 12,000-mile warranty

GET A QUOTE Get a fair and transparent estimate upfront

Cost of Replacing a Bad or Failing ECM-Power Relay

If there is no power when the key is inserted, the engine will not start, or the battery is dead, you may need to replace the ECM power relay. Our certified technicians can come to you and diagnose the problem. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. Following are example prices for ECM-Power Relay Replacement. Click on the button below to get an upfront quote for your car.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2010 Kia Sportage $89 $19.18 $70.00 29% $126.68
2003 Mitsubishi Montero Sport $106 $35.98 $70.00 26% $143.48
2006 Dodge Magnum $97 $26.98 $70.00 27% $134.48
2010 BMW 135i $88 $17.98 $70.00 29% $125.48
2014 Audi A4 allroad $98 $27.58 $70.00 27% $135.08
2009 Porsche Cayman $90 $20.38 $70.00 29% $127.88
GET A QUOTE FOR YOUR CAR Get a fair and transparent estimate upfront

How to Diagnose a Bad or Failing ECM-Power Relay?

ECM-power relay

The ECM, or electronic control module, is the computer responsible for controlling all of the engine management functions. It is the central control unit of most vehicles and controls a variety of functions, such as electrical system power distribution, emissions, ignition, and fuel systems. It is a very important, if not the most important component of a modern engine management system, and just the same as any other important electrical component it is powered through a relay.

The ECM power relay is the relay responsible for sending power to the ECM. If the relay fails, or has any issues, it can cause the vehicle to have all sorts of problems, and may even render it undriveable. Usually a problem with the ECM power relay will produce a few symptoms that can alert the driver of a problem that should be serviced.

1. No power when the key is inserted

One of the first symptoms of a problem with the ECM power relay is no power when the key is inserted. If the ECM power relay fails it can cut off power to the entire vehicle. A failed relay will disable the dash lights and warning chimes that normally come on when the key is inserted into the ignition, and will probably be unable to start or turn over the vehicle.

2. Engine will not start

Another common symptom of a problem with the ECM power relay is an engine that will not start or turn over. The fuel and ignition systems, as well as several other engine management functions, of many vehicles are controlled by the ECM. If the ECM or it’s relay fail, the entire engine management system will be left without power and will not function as a result. A bad relay may cause the vehicle to crank, but not start, or sometimes not even crank at all.

3. Battery drain or dead battery

A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off. This will place a parasitic drain on the battery, which will eventually cause it to go dead.

The ECM power relay is one of the most important relays as it provides power for the vehicle’s computer system. Without it the entire engine management system will be disabled and the vehicle will not run. For this reason, if you suspect that your ECM power relay may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the relay should be replaced.


Fast and easy ECM-Power Relay Replacement service at your home or office.

Get a fair and transparent estimate upfront

Recent ECM-Power Relay Replacement reviews

Excellent Rating

YourMechanic ECM-Power Relay Replacement Service

Average Rating


Number of Reviews


Rating Summary


31 years of experience
174 reviews
31 years of experience
Charles worked quickly and was very professional. He diagnosed my problem within minutes and was able to come back and fix it the next day. I am very happy with him.


12 years of experience
235 reviews
12 years of experience
Jose knows exactly what he is doing. I would recommend him to any and everyone. Told me what the actual problem was and its being taken cared of.


18 years of experience
501 reviews
18 years of experience
Joel arrived on time and ready to get to work. His appearance is very professional and he is polite and knowledgeable. He determined the most likely cause of the issue (it's intermittent, so hard to diagnose for certain) quickly and made a follow-up appointment for the following morning, on a Sunday to replace the part. He is a very nice and personable man. I enjoyed meeting him and speaking with him.


18 years of experience
445 reviews
18 years of experience
Phenomenal! He was very polite and courteous not to mention he really knew what he was doing! He explained everything to me in a way I could understand. So glad I called! I'll be referring Richard to all my friends and family. Should I ever run into car trouble again, I'm hunting Richard down! Lol... Keep up the good work and have a blessed day!

More related articles

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)...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...

Related questions

Q: What is an ECM-relay and where is it located?

Hey there. The ECM relay on this vehicle is called an auto shutdown relay and is located in the engine compartment integrated power module control box. The P0052 code you are getting is for the passenger side O2 sensor closest...

Q: How do you know if the ignition needs to be replaced when you replace the plugs on dodge 5.7 hemi?

Hi there. To determine if the ignition coils need to be replaced, remove one park plug wire at a time and hook it up to a spark tester gauge and set the gauge to 10 thousands gap and increase it...

Q: Q: Clicking sound when trying to start the car

It sounds like you will need to have the starter checked. You'll need to check if the click is coming from the starter solenoid on the starter or the relay in the power relay box in the engine compartment. Also,...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 ·