Skip the auto shop - Our mechanics make house calls

Q: just replaced motor in 2007 mazda 3 check engine light won't go out. what could cause this.

asked by on

Looking at buying Mazda 3 , 2007 runs and drives perfect owner had engine replaced and the check engine light won't go out. Any thoughts?

My car has 107000 miles.
My car has an automatic transmission.

The check engine light comes on to indicate that the Electronic Control Unit (ECU) has detected a fault in the engine management system. When that happens, there will be a code stored to represent the malfunction. The codes can be read with the appropriate scanning equipment and a technician interprets the code and decides what steps to take. It’s not uncommon to see a check engine light after an engine replacement, often it means that the engine wiring harness wasn’t hooked up completely right on the first try. But the light won’t go out until the fault is repaired and the ECU cleared of codes. That said, I’d be wary of a car that needed an engine replacement. Often that happens because the car was poorly maintained, and that can mean there might be other problems lurking as well. For a little peace of mind, you might contact Your Mechanic for a pre-purchase inspection. They can send a technician to the location of the car to check it out for you and let you know what you can expect from the car.

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
  1. Home
  2. Questions
  3. just replaced motor in 2007 mazda 3 check engine light won't go out. what could cause this.

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: Should I change my engine oil?

The best answer for you would be no i would not recommend changing the oil unless you look at the oil on the dip stick and it is not clear or is milky looking from excessive moisture in the oil....

Q: Vehicle stalls while reversing

Hello. The power steering in your 2007 Chevrolet Express is run off of vacuum from the engine. If there is a vacuum leak in the engine’s system, it will cause the problem that you are experiencing. The brake booster is...

Q: Speedometer is not working

The Check Engine Light on with the speedometer not working may be an indication of a failed VSS (Vehicle Speed Sensor). Fault codes should be read out of the engine computer, and if there is a fault for the VSS,...

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...
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.