Check Engine Light Not On But Codes Found

Disconnect that circuit from the ecu if the light goes off probably an issue with the ecu if the light stays on look for a short to power on that circuit.

Check engine light not on but codes found.

However all error codes are stored so you can look at historical data even with a 10 bluetooth obdii dongle and see what the code was before. But if the problem is not emissions related and also not critical it may be stored in the computer but not light the check engine light. Press the erase clear button on your scanner then turn off the key and disconnect it. After pressing erase clear and waiting until you see a no codes message you can turn off your vehicle and disconnect the scanner.

The same is true if you have abs light on tcs light on vsc light on etc. Clearing any codes present will turn off your check engine light temporarily. Generally if the light is coming on and no codes are stored the processor that triggers the light is faulty or the circuit is shorted to power. You ve only got two choices at this point.

So no codes when it was scanned. This is often the result of something being wrong with the obd reader that the driver parts store or mechanic shop is using. One main reason that a check engine light comes on with no code being stored is that there is a software error. There are other cases where there s no check engine light but codes.

If the check engine light is on you ve got a trouble code stored. For example any problem that affects the emissions system will automatically light the check engine light. Buy a scan tool that can read enhanced as well as b c and u codes or pay a shop to read the codes for you. In that case you could scan the computer and find a code even though the light wasn t on.

Most frequently the software errors stem from a low level obd reader being used.