Chevy Cruze P1101 and P0171 Trouble Codes

Far and away the most common trouble codes on the Chevy Cruze are P1101 and P0171.  They are OBD-II trouble codes.  These codes will trigger the service engine soon light when the ECM receives a signal from them that is out of range.

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P1101:  MAF Out of Self Test Range

Chevrolet Cruze P1101 Trouble Code

P1101 is one of the most common of the Chevy Cruze trouble codes.  Whenever you start the vehicle, the mass airflow sensor does a self diagnostic.  If the results of this test are out of range, than the P1101 trouble code is thrown.

There are a number of issues that can cause the mass air flow sensor to fail the diagnostic.  We’ll list them in the most to least likely to have happened.

Chevy Cruze P1101 Causes

Engine Wiring–  A good place to start is to do an inspection of the area around where the mass airflow sensor plugs into the intake. Make sure that the wiring doesn’t look broken or disconnected.  You’d be surprised, in the winter months a rodent can cause a lot of damage to a an engine in one night.

Air Filter–  Pull your air filter and see if something has gotten in there.  If it has, remove the debris.  Or if the filter looks very dirty go ahead and replace it. If enough air is not getting into the engine the mass airflow sensor is not going to get a proper reading, and P1101 will likely be thrown.

If neither the engine wiring or the air filter seems to be a problem, then it’s going to be time to pull the mass airflow sensor and see if it is dirty.  A word of caution, these sensors can be incredibly sensitive to the oil’s on skin so make sure to use caution and not touch the sensor element itself.

Leaking Intake–  If the intake seal on the Chevy Cruze has been damaged, there’ll be a vacuum leak.  A vacuum leak means that air will be getting in to the intake not through the throttle. This is going to dramatically alter the reading at the mass airflow sensor gets and will trigger P1101.

A mechanic would be able to do something called a smoke test, which would let them visually see where the intake is leaking from.

If you would like to try to find the vacuum leak yourself go ahead and perform a visual inspection and make sure that you don’t have a disconnected or broken vacuum hose.  If it looks ok, than carb and choke cleaner can help.  Here’s a good video on vacuum leak diagnosis.


MAF Sensor May be Bad–  at this point the only cost that we should have incurred is the cost of a can of carb and choke cleaner.  If everything checked out, and there were no intake leeks, than it’s time to evaluate whether the MAF sensor is bad.

Here’s another YouTube video.  This one goes over how to test a MAF sensor with a multi-meter.  It’s relatively easy to do and multi meters are cheap.


Will the P1101 code make the Cruze stop running?

The P1101 code typically will not be enough to make the engine not run.  A bad mass air flow sensor is enough to make the engine:

  • Idle poorly
  • Consume more fuel
  • Lose power

If left unchecked, a bad MAF sensor can lead to other engine problems.

P0171:  Fuel Trim System Lean Bank 1

Chevy Cruze P0171 Code

There are many different problems issues than can cause the Cruze’s computer to throw the P0171 trouble code.  It’s more than likely going to be an intake leak of some sort that is causing the issue.

Unlike the P1101 code listed above, the P0171 code can be caused by a lot a Myriad of issues.

Chevy Cruze P0171 Causes

Intake Leak–  An intake leak is where you need to start thinking about solving the problem.  If your Cruze is also throwing the P0174 code, it’s highly likely that the intake is leaking somewhere.  There’s a video embedded in this article on how to find an intake air leak.  Scroll about halfway up, you’ll see it.

Misfire–  A vehicle doesn’t have to misfire a lot to throw the P0171 code.  If the car is already misfiring than fixing what’s causing the misfire should clear the code.  It gets trickier when it’s not so obvious that the car is misfiring. A good way to figure it out is to listen at the exhaust pipe for a minute and see if you can hear a burble sound every now and then.

Bad Oxygen Sensor–  A bad oxygen sensor can make the computer lean out the air fuel mixture and throw the code.

Bad MAF Sensor–  A bad mass air flow sensor can cause the P0171 code to throw, and often does on a Chevy Cruze.

Here are a few other things that have been known to throw this trouble code, but they are less likely to be the culprit.

  • Fuel Injector’s
  • Fuel Starvation
  • Fuel Pressure
  • PCV Hose (although it only takes a second to inspect)

If you do end up deciding that it’s the mass airflow sensor, make sure that you replace the air filter or at least inspect it before doing so.  A clogged air filter can give the same conditions as a bad mass airflow sensor.  Check it and see if it is dirty. They only take a second to clean. There’s a video on that a few paragraphs up in the P1101 section.