What causes check engine light to come on in Honda accord 2004?

Answer 1

In todays motor car we have an huge amount of electronic "junk" that is a pain. (and costly to fix as almost all mechanics have no idea about electronic, so they flood the car with costly parts till the light problem goes away) If your "check engine light comes on stop the vechicle turn off the engine and wait till the motor has cooled down... check the coolant system (use caution with an over heated engine when you lift the radiator cap) and check the levels in both the radiator ,and coolant recovery bottle...WARNING...some cars have no radiator cap and you can not see in the radiator to check the coolant level, you can only see the recovery bottle. If the engine coolant is leaking, the sealed system is opened to the atmosphere and the recovery system will not work.....RESULT a bottle still showing "full" but you will have no coolant in the engine. This is a common problem with "SUPER DOOPER" BMW cars along with their plastic radiators. CURE.. to see what you have in you radiator, ask you mechanic to remove the thermostat from its housing, when the engine is cold, squeeze the BOTTOM radiator hose and you will see water squirt into the recovery bottle from the top or header tank, this will tell you that the RADIATOR is full. With this type of system this is the only way you can be sure. you must remove the thermostat as .if you don't, it will stop you from pumping the water into the recovery tank by squeezing the hose, the water simply wont move. Now, is it a problem driving with no thermostat...NO, your engine simply will take a little longer to warm up and so will the heater. Will it hurt the engine NO, you engine will run somewhat cooler....the next step. after the engine is cool dip the oil , check all brake/clutch fluid levels and automatic fluids, belt tensions and any and all you see fit. If all is well your problem is a light that is playing up. Most "light" problems are caused by a broken wire at the connected engine point, in fact most auto electronics faults are traced to a bad ground (earth) Last , since this light is coming on at times WATCH YOUR TEMP METER LIKE A HAWK as well as you OIL LIGHT / GAUGE. If you find no problem with coolant ,oil etc, you can be reasonable sure it is a dicky light ( MOST ANNOYING).. LET'S go back to the seventies when we did not have all this electronics auto junk built into cars, i have a 1989 4WD that i spent a lot of dollars on , in fact a fully rebuild from stem to stern. it has no bloody electronic junk and i can service / repair it in the back country with no problem. The only people who understand today's cars are the bloody engineers who designed them, do not expect you local mechanic to understand the electronics, it is way above his training.