What happens if the power door lock relay fails?

If the power door lock relay fails, it will cut off power to the entire power door lock system and may cause them to not function correctly. For vehicles equipped with door lock cylinders, the door can still be opened using the key.

What to do if your ECM power relay is failing?

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. The most popular service booked by readers of this article is Vehicle Engine Electrical Inspection.

What are the causes of a relay to fail?

Relays fail for a variety of reasons (see article: What Causes a Relay to Fail ). Some are accidents, some are caused by manufacturing defects, and some are simply end-of-life failures. Different relays fail in different ways.

Can a DMM check for a relay failure?

Users can also use a DMM to check for relay failures, but some caution needs to be exercised on high current relays. These relays typically have a minimum operating current/voltage that is needed to overcome surface films that can accumulate on the contacts.

What happens when the relay is not activated?

When the relay is not activated, this circuit is ‘open’, and as such, does not send any power to anything. Both of these circuits are completely independent from one another, since the voltage/current flowing thru’ them don’t mix. To get into more specifics, this is what happens when you turn On the Key and crank the engine:

What causes a door lock relay to not work?

Power door locks do not function. Power door locks that do not function are another common symptom for a problem with the door lock relay. If the power door lock relay fails, it will cut off power to the entire power door lock system and may cause them to not function correctly.

What are the symptoms of a bad ECM power relay?

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.

Is the EEC power relay easy to recognize?

The EEC Power Relay is easy to recognize because it’s usually a brown color. If the EEC Power Relay has already been replaced, you can still recognize it by its brown colored connector. In this ‘how to’ tutorial, I’ll show you how to test it on your Ford car or pickup in a step-by-step manner.