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Jeep Wrangler JK: How to Check Engine Codes

The Jeep Wrangler is equipped with a computer designed to point out the faulty components. This guide will help you understand how to check for engine codes.

By Bassem Girgis - November 16, 2015
Contributors: Wayalife.com

This article applies to the Jeep Wrangler JK (2007-Present).

Your Jeep Wrangler has tons of components that play a role in making it the car that you drive today. Almost all of the little components are wires to sensors, so when they go bad, it notifies your Jeep's computer and the computer notifies you with a code. The folks that designed the Jeep made it even easier; now you can check for engine codes without even using an OBD-II scanner. This articles will go over the sequence to get your car to tell you what's wrong with it. Read on to learn how to check for engine codes in the Jeep Wrangler.

Figure 1. Engine code on instrumental panel.

Materials Needed

  • No tools needed

Step 1 – Understand how to read codes

The engine codes are made out of five digits.

The first digit is a letter. You may have one of four letter: B (body), C (chassis), P (powertrain), or U (network).

The second digit will be either a 0 (SAE) or a 1 (MFG).

The third digit indicates one of eight things: 1 (fuel and air metering), 2 (fuel and air metering injector circuit), 3 (injection systems or misfire), 4 (auxiliary emissions control), 5 (vehicle speed control and idle control system), 7 and 8 (transmission).

The last two digits indicates the faults, which can go from 00 to 99.

Step 2 – Turn key to ON position

Insert your key into the ignition and turn it to the ON position, but don't start the car. Push the key into the ignition and turn it to the OFF position, while holding it in. Then turn it back to the ON position. Repeat this process three times in a row and stop on the ON position on the third time.

Figure 2. Turn the ignition from ON to OFF three times, while pressing it inside.

Step 3 – Read the code

When and if you do Step 2 successfully, the dash light will turn on and off, then a code will appear. Take a note of that code. However, if you get a massage that says "done," it means you have no codes to read. If nothing happens after Step 2, repeat it and be sure you are not waiting too long between turning the ignition on and off.

Figure 3. Engine code.

Pro Tip

To check the code, visit Wayalife or Quadratec sites. They offer a full list of codes for the Jeep Wrangler.

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