What does it mean when my engine check light comes on?
Your engine ECU has detected an error from your engine. The error will be depicted as an error code pointing to the fault. Diagnosing the fault may be more involved than just simply changing a component or sensor.
Sensor failure:
- If a component has failed like a crank sensor, camshaft sensor or MAF sensor the engine will probably stop running as these sensors give critical information to the engine to make it run. The info would include how much fuel and air to supply and when to ignite the mixture thereby making the engine run.
- Before swoping out a sensor you should test it to make sure it is indeed faulty as theses components are often awfully expensive and may not resolve the issue.
- For example, a fault from an oxygen sensor especially after work has been done on the vehicle will probably indicate poor assembly. It would point to a vacuum leak or poor fuel supply.
- Multiple sensor failure is highly unlikely unless you shorted out the system, water damage or something drastic happened.
Diagnosing the problem.
- If the engine is running with a component error, it may well be pointing to a mechanical fault like a vacuum leak a fuel supply problem or a fault with the spark system. To fully understand the fault, you need to read live data stream to point you to the actual fault.
- Comprehensive testing will not only point you in the right direction but save you a ton of money and time.
Live data streaming.
What dose live data streaming mean?
- A good ECU diagnostic tool will allow you to select components on the engine to monitor while the engine is running.
- You will select components like fuel pressure, cam and crank timing, misfire by cylinder and any other component that may be related to the error you are receiving. This will allow you to see if a sensor has failed or it is out of range due to mechanical error.
- The other benefit of using an advanced diagnostic tool it the ability to activate individual components to see if they are working. Components may include but are not limited to fuel pump, fuel injector, cooling fan and many more.
- Testing individual components via you ECU system is far more cost effective than trying to test the components by other means.
Resetting controllers.
When will it be necessary to reset a controller?
- Often some electronic system will stop working that are controlled by onboard controllers forming part of the vehicles computer system. A simple reset could often clear the error and the system will start working again.
- Two cases I have experienced is a fuel pump not working. The client spent months removing the pump testing fuses and relays without success and at great cost. The fuel controller unit was then rest, problem solved no stripping, climbing under dashboards and a hell of a less frustration. The second case was with the power windows and central locking not working. This time no other work was carried out other than resetting the door control module problem solved in minutes.