How do you know when the computer in the engine is gone bad

Car will not run!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The crank sensor gives the ecu info regarding engine speed, etc. and if it is not working neither will your computer - your spark plugs will not fire either.

saw your comment

may not be the solenoid

did you use a scanner to let you know if it's that?

it's under fail safe mode right now, not allowing you to go past that speed

in my case, the trouble code

FOR MY vehicle was a bad Vehicle speed sensor

and had set the check engine light as well

autozone, advance auto parts, and aamco transmissions can scan the car's computer for free

Just like your engine computer stores codes and turns on your check engine light, your ABS computer stores codes and turns on your ABS light. You can retrieve these codes with a scan tool, but it has to be one that can communicate with your ABS computer. The less expensive scan tools just will not do this, I would suggest taking it in to a shop and having the codes read, then you can decide if you want to fix the problem yourself or have a shop do the repairs. Chances are good that it would just be a wheel speed sensor gone bad, but you just don't know or know which one without having the computer scanned.

Yes, you can get codes without the light being on. They are in a History and although the light may have gone off *(SOFT CODES) then they are still in the history.

The computer is what supplies current to the injectors and that flow of current is regulated by a crank or cam sensor. Have the engine trouble codes on the vehicle read, to know for sure what's gone bad.

Do you have a check engine light on? If not, it could be many things from bad fuel pressure, a vaccum leak, or your not getting a good connection in the ignition system. Check the fuel pressure to the engine first. If that checks out, write me back. I am here to help in anyway I can.

Has it had a recent tune-up? It is important for the spark plugs and wires to be in good shape. It is also important for the air filter to be clean. What sensors did you replace?

If the mass air-flow (MAF) or manifold absolute pressure (MAP) sensors are bad, it can cause this issue because the computer doesn't know how much fuel to add if it doesn't know how much air the engine is getting. This can also be a result of a bad throttle position sensor (TPS) because the computer doesn't know how much demand you are putting on the throttle (how far you are pushing the gas pedal) so doesn't know how rich to make the fuel mixture. If any of these sensors have gone bad they usually set a code in the computer. Even if the check engine light isn't on, there could be a pending code in the computer that can be found with a hand held scanner. Auto Zone will read the codes for free or if you can't drive it, you can rent or buy the scanner yourself. Be sure to write down the codes you get and post them here. If you are able, you can also test the fuel pressure. Low fuel pressure can cause the issues you are having too.

Hello,when the check engine light comes on this means that some part on the engine has failed( oxygen sensor,relay,emission part,coil,injector,ect) the dealer will charge you around $100.00 to run a diagnostic test on it!! but you can swing by any auto-zone parts store and they will run a test on it for no charge( they have a hand held little computer that plugs in under your dash.) and tell you which part is gone bad on your suv,which you can purchase from them and replace yourself,or at least take to shop and tell them which part is bad saving your self the $100.00+ dollars for finding the problem....yz-maniac.

You can not bypass it,as the computer won't won't know how much air is entering the engine and won't run without it.

You could get a used one at the bone yard or Napa for $100 to $200 depending on application.

How do you know it is bad?? What type of test was done to suspect it?

If it's a gas engine you can find it in the back of the motor on top somewhere around the distributor. If it's a diesel its on the lower left hand side of the block just below the engine computer