# checking engine light on, and then went off. Do I need to go to dealer to reset



## titan2782 (Nov 4, 2011)

If the light went off then that means the computer thinks the problem has gone away. However, the code will be stored in memory and will be visible with a code scanner. You can get yourself an OBD2 adapter from Amazon and the Torque app on an android/iphone or you can try windows software (I dont know which ones) and you can clear the codes yourself.

Soliport ELM 327 Bluetooth OBDII OBD2 Diagnostic Scanner : Amazon.com : Automotive

This is the one I kept. I also bought a BAFX. It was more expensive but Torque app said it was a POS clone so I gave it to my brother-in-law 

As far as disconnecting the battery, I don't suggest it. Usually it makes the light go away (in older cars at least) but I think the code will still be stored but it would be best to just clear the code using a hand held.


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## jblackburn (Apr 14, 2012)

Any chain auto parts store (Advance, Autozone) will pull the code for you for free. Some will even reset it. Like Titan said, the code should still be stored in the computer. Just because the light's not on anymore just means the code hasn't triggered again (which you fixed by tightening the oil cap).

However, for the light to trigger in the first place, the condition that caused it to set must occur multiple times. After a few driving cycles with no condition, the computer will delete the code from its memory.

Don't yank the battery cables. While it may re-set the code, the car has to re-learn all the adaptives it's stored in the computer again. Fuel trims, shift points, etc.


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## NickD (Dec 10, 2011)

I'm still up in the air on this subject, with the advent of OBD II enforced in all 1996 USA vehicles, a common diagnostic connector is to be used with common codes. Nothing like that today. In 1996, GM came out with the GM Tech II scanner that also required yearly updated firmware for new and different codes.

With a generic scanner, really don't know precisely what P071 code is. If going by GM Tech II traditional standards, P071 code can be any of the following:

Essentially, the engine is running lean and can be caused by any of the following, running an engine like this can burn up the exhaust valves. But you are reading a generic code, no telling at this time what it means. All this stuff is even new to my dealer.

Cruze does not use the OBD II system, but a new generation III system, would definitely take it to your dealer for inspection. Fuel pump or regulator problems means draining and dropping the fuel tank.



PCM software needs to be updated
Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.)
Mass Airflow Sensor (MAF)
Plugged Fuel Filter or weak Fuel Pump
Plugged or dirty Fuel Injectors
Faulty fuel regulator.


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## jblackburn (Apr 14, 2012)

It was most likely caused by the vacuum leak from the oil cap/dipstick.


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## Nikon1234 (Nov 25, 2012)

Hi. 

thanks for the quick replies. 

So according to "jblackburn", the code will be deleted after a while ( After a few driving cycles with no condition, the computer will delete the code from its memory.)

If that is the case, I think I will be doing nothing to the car. That is the solution I want to take.

Thanks. again.

Dan


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## sciphi (Aug 26, 2011)

Yep, this is one case where doing nothing is the correct course of action. A CEL will generally go out by itself once the offending condition has been taken care of. Sometimes a reset of the PCM is necessary, especially if replacing a part like a oxygen sensor.


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