How to Read Codes on Jeep TJ Wrangler Without a Code Reader P0455 P1685

September 5, 2018

Learn how to read and clear check engine codes on a Jeep TJ without a code reader. Simple steps and practical tips inside!

Quick Look

Category

Maintenance, Mods, Off-Road

Vehicle Type

Jeep TJ Wrangler

Common Codes

P0455, P1685

Use Case

Read and clear engine codes

Overview

Understanding your Jeep's diagnostic system can save you time and money. In this guide, we’ll take a look at how to read and clear check engine codes on a Jeep TJ Wrangler without the need for a code reader. This is particularly handy for those who might find themselves in a pinch while out on the trail.

What This Covers

Most Jeep enthusiasts may not realize that they can diagnose common issues simply by using the ignition key. We will explore the necessary steps to read Diagnostic Trouble Codes (DTCs) and how you can clear them, along with a discussion of two common codes that might come up: P0455 and P1685.

Step-by-Step Breakdown

1. Insert the Key: Begin by inserting your key into the ignition.
2. Turn the Key: Turn the key to the 'On' position three times in quick succession without starting the engine (i.e., On-Off-On-Off-On).
3. Read the Codes: Watch the dashboard for codes to appear. In this case, we retrieved P0455 and P1685.

It's that simple! Now let’s break down these codes:

• P0455: This code indicates an EVAP system leak, commonly due to a gas cap that isn't securely fastened or has a faulty seal. This is a frequent issue and often easy to fix.
• P1685: An 'Invalid SKIM Key' code generally results from an issue with the ignition key, such as trying to use the wrong key to start the vehicle.

Helpful Tips

When troubleshooting the P0455 code, always start with the gas cap. Ensure it’s properly tightened and check for wear on the rubber seal. If the problem persists after resetting the code, further investigation into the EVAP system may be necessary.

When dealing with the P1685 code, it’s essential to use the correct key designed for your Jeep model. If you ever accidentally try another key, the vehicle won't start due to security protocols, and you’ll see this code pop up until resolved.

Key Takeaways

Reading and resetting codes on a Jeep TJ is straightforward and can be accomplished without specialized tools. For off-road enthusiasts, being able to troubleshoot minor issues on the go can make a significant difference in your adventure experience. Always remember to check the basics first—many problems, especially related to check engine lights, often come down to simple fixes!