DTC P0102 Mass Air Flow Circuit Low Frequency

When a DTC is stored in the PCM, (Power-train Control Module) you would figure that the stored code would point directly to the fault or the engine would run poorly.

Some codes will be very specific to a sensor or fault condition.

DTC P0102 is a simple code with a very specific fault condition. The MAF signal is low during engine operation. The normal idle frequency of a good GM MAF is around 2100 to 2500 hertz.

The code will most commonly set anytime the hertz signal drops below 1200 hertz during engine operation.

This condition is easy to check with a lab scope or a OE level scan tool. I do not recommend to DIY this type of intermittent fault unless you have the correct tools. It is easy to cause more harm than good or replace parts that are still good.

If the condition is intermittent it could take time to duplicate the fault. Many parts houses will sell you a MAF sensor as the most common part replaced. When the condition is intermittent you have to duplicate the condition to I.D. the real cause. The MAF sensors can go bad, but MAF sensors are not the most common failure part.

Do not buy a re-manufactured MAF, ever!

A man-made or age related failure is more common with an intermittent fault. I see many damaged electrical connectors, faulty Idle Air Control Valve, poor handling of the wire harness during service work, damage to the MAF sensor, poor quality accident repairs, faulty chassis grounds or age related circuit failures may cause an intermittent conditions.

This dirty throttle chamber was causing the clients issue. The build up was cutting off the air and causing the engine to dip so low in RPM that it would go into a stall when coming to a hard stop.

One week earlyer I had a Buick Park Ave that had the same code, but it had a bad MAF sensor. Testing is the best way to know what is faulty. If you have a check engine light on. Stop in to the shop and let us take a look.

It’s all good under the hood. Anthony Xavier ASE Master Technician

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