Hi there. It is possible that the ECU is damaged; however, it could be a simple problem like a damaged fuse, damaged electrical relay or problems with the dashboard itself. It’s best to have a professional mechanic to complete a check engine light inspection. This will allow the mechanic to attempt to access the ECU with the scanner. If it connects, then the issues are much easier to resolve. Replacing an ECU can only be done by a dealer; or authorized Mazda mechanic, which can get rather expensive.
How to Identify and Fix Common car Problems ?
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the check engine light should come on when key is turned to on. cluster does a bulb check every time key is turned to on. if it is not coming on,then it could be a fuse or the bulb its self is burned out in the cluster. check owners manual,and or fuse box lid/cover for fuse location first.
A check engine light will shut itself off if the condition that caused it is remedied. So, if your converter is marginal, and you did a lot of stop-and-go driving, which creates high demand for the converter, that may have turned on the check engine light.
However, if there`s a problem, the light will come back on as soon as the computer runs the test that caused the light in the first place. It might happen right after you turn the car on, which might make it seem like you can`t clear the check engine light. Or it might take a couple of days to come back.
There is no fuse for the check engine light. If it`s not working (i.e. if it doesn`t light up as part of the ignition sequence), chances are it was deliberately deactivated to hide a major issue and dupe you, the buyer, out of more money.
In short, yes; it`s possible to diagnose a problem with a vehicle even if the check engine light does not illuminate.
It`s absolutely normal for the engine light to turn on when starting the vehicle, and it should go off after a few seconds. Otherwise, if the light stays or turns on when you`re on the road, you can do the following: Check the fuel cap and tighten it if it is loose. If the light goes away after this, you`re good to go.
The check engine light should go off after you drive for several minutes if the light was caused by a loose gas cap. Pay attention to the dashboard after the check engine light experience. If you find that the light keeps coming on, and goes off again once you tighten the gas cap, then your gas cap is too loose.
Press the odometer`s Trip and Reset buttons while turning the ignition key ON. After turning the key ON, release the odometer Reset and Trip buttons to check if the Diagnostic Trouble Code or DTC appears on the odometer display.
Disconnecting your battery and draining the power to cause an ECU reset is one of the most common fixes for a check engine light that won`t go away on its own. Doing so is equivalent to a hard reboot on a desktop computer, which is a standard way to eliminate many common problems.
The check engine light illuminates when your vehicle`s computer believes there is a problem that could affect — or is affecting — your car`s emissions control system. When the light comes on, one or more diagnostic trouble codes are stored in the car`s computer. These codes will stay there even if the light goes out.
Blown Fuse. If you`ve plugged into your car`s diagnostic port and aren`t reading anything, you might think that your OBD-II brain has been fried, but don`t declare it dead yet. The most common reason for getting no OBD code is simply a blown fuse.
If there`s no Check Engine light or any codes that might suggest an O2 sensor related fault, he has no way of knowing if any O2 sensors need to be replaced. The only clues may be a loss of fuel economy, or elevated carbon monoxide emissions (if a pre-OBD II vehicle fails a tailpipe emissions test).
One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn`t working, the spark plugs won`t fire, keeping the engine from starting.
Bad Gas, What are the Symptoms? If you`ve inspected the gas cap, the problems you are having may be due to contaminated fuel. If a car, truck, or SUV has trouble starting, will not accelerate, or just is not running smoothly, then it`s possible you just have a contaminated tank of gas.
Many manufacturers recommend tightening the fuel cap until it clicks three times, which is just a random number to make sure the cap is tight. At this point — even though the engine will run fine — it would be best to bring the car into have it looked at.
The easiest method to reset the check engine light is to drive your car as you normally would and let the light turn off naturally by itself. If it hasn`t turned off after three days, turn the car on and off three times consecutively.
Can I Check My Own Light? You can. All you need to check your light is an OBD-II reader, which can pull codes that help you find out what`s wrong with your car.
Car Scanner ELM OBD2
Car Scanner ELM is an easy-to-use app that allows you to view any DTC`s (Diagnostic Trouble Codes) that your vehicle might have accumulated. This app is one of the best OBD2 apps for Android as well as iOS.
It really depends on the ECU, the car itself, and what year car it is. Also, it depends on what is being relearned. Some things, like short term fuel trims can be learned in as little as 20 miles. Other things like long term fuel trims will take longer, maybe 80 to 100 or more miles.
To make sure the check engine light does not reappear, it`s recommended that you drive your car 30 to 100 miles. This enables the vehicle`s “Drive Cycle” to reset, as the various sensors need time to recalibrate.
Engine misfires, rough idling and hard starts can all be traced to a clogged engine air filter. The dirty air filter restricts the air supply to the engine causing unburned fuel to form a soot residue that accumulates on the spark plug.
Incorrect filter installation or installing the wrong filter can leave your engine open to dirt and debris. When the engine`s air intake is not completely covered by a filtering element, extensive damage can occur.