Skip the auto shop - Our mechanics make house calls

Q: ECU related

asked by on

Hi this is a funny story actually. My Saab had trouble starting. Everything electrical would turn on but the car wouldn't start. There would be some clicking so we went ahead and changed the starter. We still had the problem. One day I hit the top of the electrical control unit out of frustration and it magically turned on. So now every time the car wont start I hit the same spot with my hand and it turns right on. I'm thinking there is a short possibly but hitting it works. Please help!

My car has 93000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. By the informati...

Hi, thanks for writing in. By the information you’ve provided, it sounds like there may be a connection inside the ECU that has broken. When a soldered connection breaks due to vibration, or an impact, sometimes there will be a hairline crack in the solder. There will be just enough of a gap in the solder that it won’t make contact, and when you hit the top, it can close up the gap and make just enough contact to allow normal function for the moment. If this is the case, it will get worse over time and quit working all together. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

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!

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: What is causing the truck to not start? 1995 Ford F-150

Hi there. It sounds like either a battery or starter that is faulty. Perform a test on the battery with a digital battery tester that provides the cold cranking amps and state of health. Then perform a voltage drop test...

Q: Whan engine is warm, it shuts off and won't restart

Hello there, thank you for asking about your 1985 Dodge Ramcharger. We must determine what is going on when the engine is warm that causes the no start. The proper fuel pressure and ignition signals must be present or it...

Q: Coolant level dropping quickly 2006 Saab 9-3

Hi there - yes, I would say this is a problem. Coolant loss can be deceptive - failing water pumps will sometimes only leak while running, blown head gaskets can leak into the engine crankcase, turning the engine oil to...

Related articles

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.