It no longer is accurately tracking how hard the fuel pedal is being pushed. This is readily available at any auto parts store. This enables you to spot any fleeting problems. This will cause the Cobalt to run rich. Plus, they contain full trouble code descriptions and troubleshooting instructions. I personally, coming from Boston, with all the Road Salt, etc. The code definitions are a good starting point when determining the cause of the service engine light but where do you go from there? Typically the code will be triggered by a lean condition in the engine.
One of the most common trouble codes with the Chevy Cobalt is the P0171 code. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the Engine Control Module. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. We certainly understand how frustrating it can be to look for a code definition and have it not online when you need it. YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Good luck diagnosing P0121 in your Chevy Cruze. And lets face it, if the service engine light is on then you need it now! Look up your code definition.
Continue driving and see if the check engine light turns off. © 2012 Rick Muscoplat eautorepair. Testing the throttle positon sensor and its circuit Courtesy: aa1car. When the gas pedal is depressed, the control module commands the throttle to open. Flow during non purge means the purge valve is stuck open.
It is a type of variable resistor which changes its resistance value according to throttle position. By making a good attempt to narrow down where and what may be causing the problem you save those trying to help many steps in diagnosing the problem. First, you want to disconnect the sensor connector and test for power and ground. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing. This sensor controls engine operation such as fuel cut. Most throttle position sensors are simple and easy to troubleshoot. To perform the test, the computer pulls a vacuum and checks to see if the vacuum holds.
To test the ground side of the circuit, connect the red multimeter lead to the battery positive terminal and the black lead to ground. What are the symptoms of the P0121 code? This youtube video is a great resource for diagnosing the P0171 trouble code in your Cobalt. This voltage reading increases as the throttle is opened and will read about 4. For most people the first sign that anything is wrong at all is the service engine soon light coming on. YouTube has many helpful topics. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.
If you've already made it to the store, you might as well just replace it. Now don't ask yourself; What should you do with P0121 code? Next, set your multimeter to the volts setting. Typically, the sensor should read around 4. This tells you where to start testing. When is the code detected? Chevy Cruze P0121 Symptoms The symptoms of P0121 are going to vary by year and model, but they certainly are going to cause noticeable changes in the way that your Cruze drives.
Posted on Feb 20, 2010 Circuit Range Performance error. Mess up, the next time it will be easier. What manual do you have. It often comes up with some good ideals. If it does, trace circuit for short to voltage and repair. Good luck diagnosing P0121 in your Chevy Cobalt.
With the scope, you can view the voltage signal as a wave form. Consult your service manual for it's location if you need help. The connector may have a removable cover. Here are the typical symptoms that something is wrong when you have code P0171. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control. Diagnosing it can be tricky without a good scanner and the knowledge of what you are doing.