Skip the auto shop - Our mechanics make house calls

Q: When trying to start it only clicks on a large relay (?ECU?) under the dash passenger side.

asked by on

Completely crapped out all at one time. parked it and the next day it would not show indicators or beep or nothing. slowly it started to show indicators even while the car was stopped and key removed. Then this clicking sound started under the dash on the passenger side. When I run the part number it says ECU. Does this need replacement?

My car has 85000 miles.
My car has an automatic transmission.

Often times when there is a starting issue, there is a small part called a starter relay that is many times over looked that is usually a fairly simple and inexpensive fix. The starter relay is a small unit near the starter that directs power to the starter from the battery. When this fails, it may cause a clicking sound and will not allow the starter to engage the flywheel when you turn the key. I would suggest starting with this first before going into a much more expensive repair like an ECU. If you would like to have this taken care of, a qualified professional from YourMechanic can diagnose the starting problem and guide with proper repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • When trying to start it only clicks on a large relay (?ECU?) under the dash passenger side.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Any suggestions for an intermittent starting issue?

Assuming no air leaks and/or EGR system problems such as a stuck open valve, if your car won't start without spraying a volatile, flammable substance (starter fluid for example) into the intake, that means there is a problem with the...

Q: Radio and display panel stay on after vehicle shutdown

The system is controlled by computer systems in the vehicle and the power may stay on to the radio if the interior body module is not shutting down properly. The system requires the new consult 3 diagnostic computer to access...

Q: Sluggish acceleration while in 2nd gear.

This could be traditional "turbo lag" - I would check the turbocharger boost control components for air leaks, or poor electrical connections. I would also check the throttle position sensor, which may not always be recognizing your foot pressing the...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.