# Check engine codes



## obermd (Mar 3, 2012)

What order do they appear in the list? Go after the first code first and then see what clears. Many times subsequent codes are simply reactions to the first code.


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## NickD (Dec 10, 2011)

First question is always, did you modify your vehicle in anyway?

"*DTC P1101:* Intake Air Flow System Performance

*Circuit/System Description* 

The engine control module (ECM) compares actual airflow based on throttle position (TP) to a calculated airflow based on manifold absolute pressure (MAP) sensor, and mass air flow (MAF)."

MAF uses to nichrome resistors one senses the cooling by airflow, other is a fixed reference. If the air sensor is reading lower due to oil from an aftermarket filter, will run cooler indicating more airflow. TPS could be dirty or MAP is reading low, can also be a vacuum leak. MAP goes low with more air flow.

P0106 deals with Manifold Absolute Pressure (MAP) Sensor Performance

"The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The engine control module (ECM) supplies 5 V to the MAP sensor on the 5 V reference circuit. The ECM provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM detects a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM detects a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used to determine the barometric pressure (BARO)."

On a 2.2L GM engine, was able to bench test the MAP sensor, was okay, but the O-Ring inserted into the intake manifold was rotten, replacing that not only saved $$$$ replacing the MAP sensor, but also cured the problem. Really don't know until you look.

I hate O-rings, but production sure loves them, instead of screwing a part in for a good seal, just slide it in and hope for the best. But really not intended for an automotive environment.


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## Mr5Stardriver (Oct 6, 2015)

obermd said:


> What order do they appear in the list? Go after the first code first and then see what clears. Many times subsequent codes are simply reactions to the first code.


The order of the codes i believe p0106 coms up first


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## Mr5Stardriver (Oct 6, 2015)

NickD said:


> First question is always, did you modify your vehicle in anyway?
> 
> "*DTC P1101:* Intake Air Flow System Performance
> 
> ...


Wow well that seems like alot of helpful information i appreciate that ill get my mechanic to check it out again for me and if that doesn't work guess i will be back at the dealership again


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