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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. 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: 95 blazer s10 wont crank or start

If you're not getting any click or sound at all, then it's likely that you have a problem at the ignition switch, a starter relay, or the associated wiring. In older cars, sometimes it just takes a hand under the...

Q: My motor sounds like it is forced.

Hello. It sounds like you have a transmission that is slipping from the description you are giving. Some things that should be checked when experiencing slipping symptoms are the low or dirty transmission fluid, clutch problems, failing shift solenoid, or...

Q: Heavy vibration when braking above 40 mph. Also vibrates in the steering wheel

This may be a variety of things, such as wheels and tires out-of-balance, poor alignment, worn or failing wheel bearings, worn or failing control arm bushings, or worn or failing suspension components. A wheel bearing will usually fail due...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...