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.

A: Often times when there is a starting issue,...

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

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: My car won't turn on.

Hi there. There may be a few electrical gremlins causing this problem, but at first glance I'd wager that the problem is with your ignition cylinder. Sometimes the components inside the key tumbler will become clogged with dirt, debris, dust...

Q: Knock when I turn the steering wheel

Hello, thank you for writing in. You will want to do a full inspection of the steering and suspension components. The CV joints can get damaged from sudden impacts such as you described. The axles, hubs, and steering components can...

Q: Rear differential temp light on - 2006 Subaru B9 Tribeca

Despite the connector appearing OK, this is an indication of 0 (zero) resistance or a short in this circuit. It's possible the temperature sensor on the differential is itself shorted, or there is a short elsewhere in this circuit. This...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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...