Jeep Engine Code P0301: Meaning, Causes & Fixes

Are you a Jeep user worried about the engine light turning on? Of course, it can be troublesome if you’re driving and the light pops on. However, what’s more concerning is the reason behind the light switching on. 

P0301 Jeep Engine Code

You might have heard about the P0301 code. This code is displayed on the Engine Control Module (ECM); if you have no idea what it means, you need to get an OBD-II reader to decipher it. 

What is the P0301 Code? 

When the Engine Control Module (ECM) identifies a misfire from cylinder 1 in the engine, it displays the P0301 code. Multiple reasons can cause this misfire. Hence you must get your vehicle checked. A delay in getting it checked could mean more damage. 

Combustion takes place in the engine, which builds power to drive the car. This combustion happens in the cylinders, and if this fails to happen, it causes a misfire. This leads to a sudden loss of RPM because the engine cannot create enough power. A misfire could be because of low fuel or low sparks in the engine. You need to know the root cause of what might be causing the engine to misfire. 

Symptoms of the P0301 Jeep Engine Code

There can be different reasons causing the P0301 code to show up in your Jeep. Symptoms of a P0301 code vary depending on the cause. Here are some common symptoms of a P0301 code: 

  1. A hard start or no start.
  2. Decrease in power. 
  3. More fuel consumption. 
  4. Stalling periodically, especially when the vehicle is idle. 
  5. Rough idling. 
  6. Jerking movement while driving. 

Most commonly, misfiring will lead to a feeling of low power in the car. You’ll face more issues when you try to accelerate your Jeep quickly. 

Causes of the P0301 Jeep Engine Code 

There are several causes for which the P0301 engine code can show up in your Jeep’s Engine Control Module (ECM). Let’s go through some of them:

Problem with the ignition system 

Any issue within the ignition system can lead to a misfire in the engine. These include:

  • A faulty spark plug
  • Failure in coil pack or coil-on-plug coil 
  • A faulty spark plug wire if your Jeep has plug wires 

Fuel delivery problem

There can be issues with fuel delivery in the car as well. These issues consist of the following:

  • A fault in the fuel injector 
  • Bad wiring in the fuel injector circuit, such as loose or damaged wires
  • Problems with the powertrain module, like a damaged injector driver 

Mechanical issues 

The engine can also run into some mechanical faults. These are:

  • A leaking valve
  • A worn out or damaged piston ring or a damaged cylinder wall 
  • A damaged filter 
  • A worn-down crankshaft lobe 
  • A leaking head gasket 

Any of these reasons listed could cause a misfire, so it doesn’t mean that your Jeep needs detailed and extensive repairs. You’ll have to run a diagnostic test to see what is causing the code to light up. 

Is the P0301 Jeep Engine Code Serious?

Don’t take it lightly when you see the P0301 code show up. If you’re driving, then stop the car. Any cylindrical issue, if not fixed on time, can lead to severe and extensive damage to the vehicle. A qualified and professional mechanic will help you diagnose the problem while fixing it accordingly. 

This code is considered severe since it can damage the catalytic converter that will light up the malfunctioning indicator lamp (MIL). This car part is important for the engine to function properly, and replacing it can be highly expensive. 

Also Read: Jeep Engine Code P0700 & Jeep P0300 Engine Code? [FIXED], Jeep Engine Code P0128 [FIXED], Jeep Engine Code P0441 [FIXED]

How to Fix the P0301 Jeep Engine Code?

How to Fix the P0301 Jeep Engine Code
How to Fix the P0301 Jeep Engine Code?

Here are the steps you need to take to diagnose and fix the P0301 code:

Step 1: Inspect ignition system parts 

The most common cause of the P0301 code is a failure in the ignition system. You should begin by inspecting the spark plug and its wiring for signs of damage. Check the coil pack for damage if your engine has a coil-on-plug design. 

Step 2: Check for spark. 

If there are no issues in the ignition system, an inline spark plug tester will verify if a proper spark is being sent onto the affected engine cylinder. 

Step 3: Check the injector operation 

Use a bi-directional scan tool while the ignition is on to see if the fuel injection dosage is alright. Check if there’s even a small drop in fuel pressure. Repeat it for all cylinders. The fuel drop should be the same for each cylinder. If no fuel injection issue is seen, move on to the next step. 

Step 4: Diagnose other codes

If the code remains, check for other sensory fault codes that might have been stored. If you notice any, then diagnose each one to see which might be causing a problem with combustion in cylinder 1. Go over your Jeep engine’s live streaming data to rule out a sensor fault. 

Step 5: Check compression 

After going through the above steps, if the P0301 code persists, go for a compression test. Test all cylinders so you can compare numbers. If there is no issue, then there might be a PCM failure. Even if this is rare, it is still possible for it to happen. 


The P0301 code can be a serious issue and shouldn’t be ignored. A diagnostic test will identify the root cause of the issue, and you can take appropriate measures to resolve it. However, it’s better if you get a routine checkup for your Jeep to ensure that there are no faulty and worn-out components being used. Safe driving!


Can I fix the P0301 code myself?

No. Unless you have a mechanical background, you might be unable to resolve the P0301 code yourself. 

How to diagnose the P0301 Jeep engine code?

You will be able to diagnose the issue using an OBD-II scanner. However, the scanner might also identify multiple causes for the problem. 

When is the P0301 Jeep code detected?

This code can be detected when cylinder 1 in the engine is misfiring. 

What is the cost of diagnosing the P0301 code?

It takes one hour of labor to diagnose the P0301 code. Most mechanics charge between $75 and $150 for each hour of labor.

8 thoughts on “Jeep Engine Code P0301: Meaning, Causes & Fixes”

  1. Hello ! I have a 2012 Jeep Liberty Sport 4×4 with the 3.7L engine with 108,000 miles on it. I just read your P0301 Code article and it was good info. Thanks ! My Liberty shows no symptoms. Starts easily every time, idles fine, runs great, has good power (that’s a spunky little V6), no jerky driving, does not stall. Went to AutoZone, code P0300 (multi cyl misfire), secondary code P0301(cyl 1misfire), most likely solution replace cranksahft position sensor. Took it to O’Reilly Auto Parts, same codes except no crankshaft sensor code. So I took it to the Jeep dealer, they said they found the same code (no crankshaft code) but was not sure what was causing it. They want to do what amounts to exploratory surgery. They want to start with plugs and wires, $581.50 +tax. If that doesn’t work replace the coil, $600. If that doesn’t work start checking injectors, etc. If you don’t mind I’d like to get your thoughts since we don’t have any of the symptoms. The dealer did delete the code but it came back the next day. Thank You very much ! BP


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