P0201 is one of the more common OBD-II trouble codes. It indicates that the first cylinder in the firing order has an injector malfunction. It’s generic, which means that it has the same meaning for the Cadillac ATS as it would for any other vehicle.
When the PCM sees voltage at cylinder 1 that is out of the normal operating range, it’ll trigger this code. P0201 is usually caused by a bad fuel injector or wiring issue.
P0201 is usually caused by a bad fuel injector or wiring issue.
P0201 Symptoms: Cadillac ATS
This code is usually accompanied by noticeable symptoms. Here are the most common ones:
- Misfire– If your ATS’s fuel injector is not getting enough fuel into cylinder 1, it will misfire. A misfire will hurt the acceleration of the vehicle and cause fuel mileage to suffer.
- Check Engine Light– The check engine light will obviously be on, but you may or may not get a flashing check engine light as well.
P0201 Causes: Cadillac ATS
The good news when diagnosing P0201 in your ATS is that you only need to look at the fuel injector in cylinder one, since the computer has pinpointed the location of the problem for you.
Bad Fuel Injector
Bad fuel injectors are the most common reason that P0201 is thrown by the PCM. You still want to take a look at the wiring harness. You’ll also want to test the injector. There’s a YouTube video directly above that shows how to facilitate that. A new fuel injector is relatively affordable.
Fuel injectors can throw P0201 if they are plugged, dirty, or defective.
Wiring Issue
When diagnosing P0201, taking a look at the wiring around the injector is a great place to start. You want to make sure that it doesn’t look visibly damaged.
Make sure that the voltage at the injector matches the injectors that aren’t getting the code. If they aren’t that’s a good indication that something is wrong with the wiring harness.
Bad PCM
This is the last place that you’d want to look, but a bad PCM can be the reason why your ATS is getting P0201.
Conclusion: P0201 Cadillac ATS
It’s usually not too hard to track down P0201, thanks to the fact that it is specific to the first cylinder. If there is anything you would like to add that could help the next person with their ATS, please leave a comment.