P1209 Injector Circuit Open / Shorted – Cylinder #2

How to Fix P1209 Injector Circuit Open/Shorted – Cylinder #2


If you’re experiencing engine problems and your OBD-II scanner is showing a P1209 error code, it means that there’s an issue with the injector circuit in cylinder #2. This can cause your engine to misfire, run rough, or even stall. Fortunately, fixing this problem is relatively easy and can be done at home with a few basic tools.

Step 1: Check the Injector Wiring

The first thing you should do is check the wiring for the injector in cylinder #2. Look for any signs of damage, such as frayed wires or loose connections. If you find any issues, repair or replace the wiring as necessary.

Step 2: Check the Injector Resistance

Next, you’ll need to check the resistance of the injector in cylinder #2. To do this, you’ll need a multimeter. Set the multimeter to measure resistance and touch the probes to the injector terminals. The resistance should be between 11 and 18 ohms. If the resistance is outside of this range, replace the injector.

Step 3: Check the Injector Connector

If the wiring and injector resistance are both fine, the next thing to check is the injector connector. Make sure it’s clean and free of corrosion. If it’s dirty, clean it with electrical contact cleaner. If it’s corroded, replace the connector.

car vertical

Step 4: Check the PCM

If all of the above steps check out, the problem may be with the Powertrain Control Module (PCM). The PCM controls the fuel injectors, so if it’s malfunctioning, it can cause injector circuit issues. To check the PCM, you’ll need a diagnostic scanner. Use the scanner to check for any PCM error codes. If there are any, replace the PCM.

Step 5: Clear the Error Code

Once you’ve fixed the issue, clear the error code using your OBD-II scanner. This will reset the Check Engine Light and allow you to see if the problem has been fully resolved.


Fixing a P1209 error code may seem daunting, but it’s actually a relatively simple process. By following the steps outlined above, you can diagnose and fix the issue at home without having to take your car to a mechanic.


1. Can I still drive my car with a P1209 error code?

It’s not recommended to drive your car with a P1209 error code. This can cause further damage to your engine and potentially lead to more expensive repairs.

2. How much does it cost to fix a P1209 error code?

The cost of fixing a P1209 error code will depend on the cause of the issue. If it’s a simple wiring or connector problem, it may only cost a few dollars to fix. If the issue is with the injector or PCM, it could cost several hundred dollars.

3. How can I prevent a P1209 error code from happening again?

To prevent a P1209 error code from happening again, make sure to keep up with your car’s regular maintenance schedule. This includes changing your oil and air filter regularly, as well as having your fuel injectors cleaned periodically.