P0440 Jeep Wrangler: Understanding and Fixing The Evaporative Emission System Fault

Today, we’ll be addressing a common issue with the 2012 Jeep Wrangler Sports Unlimited: a code for p0440, which indicates an EVAP system malfunction. This particular code isn’t specific to a certain part of the EVAP system, so it could be related to a purge solenoid, large or small leaks, or a canister failure.

To identify the problem, I conducted an EVAP leak test using a smoke machine borrowed from a local auto repair shop. The test revealed no leaks, prompting me to move on to the next step, which involved testing the ESIM (EVAP System Integrity Monitor) switch.

Using a scan tool, I was able to determine that the ESIM switch was failing. Replacing this part is relatively inexpensive, around $70 from the dealership, including the seal. I’ll walk you through the process of replacing the ESIM switch.

I used an OBDII scan tool to perform a system check and access the EVAP system monitor test. This allowed me to confirm the failure of the old ESIM switch and later demonstrate the successful test with the new part installed.

After showing the step-by-step replacement of the ESIM module, followed by the retesting process, the new ESIM switch proved to be effective as the test results indicated a pass for the large leak test.

In conclusion, if you’re encountering the p0440 code on your Jeep Wrangler, it’s essential to diagnose and address the specific component causing the EVAP system malfunction. In my case, it was the ESIM switch, but it’s always recommended to perform thorough testing before part replacement.

Hopefully, this guide has been informative and helpful in resolving similar EVAP system issues. If you found this information valuable, feel free to like and subscribe for more automotive repair videos in the future!

What is the code P0440 for the 2012 Jeep Wrangler Sports Unlimited?

The code P0440 indicates an EVAP system malfunction, which does not specify a specific part of the EVAP system causing the issue.

What steps were taken to diagnose the issue?

The steps taken to diagnose the issue included performing an EVAP leak test using a smoke machine and testing the ESI AM switch to identify the failure.

How was the ESI AM switch tested?

The ESI AM switch was tested using a scan tool to check its status and performance during the testing procedure.

What was the result of testing the ESI AM switch?

The testing revealed that the ESI AM switch was failing and needed to be replaced.

How was the ESI AM switch replaced?

The ESI AM switch was replaced by removing the old part, replacing the seal, and installing the new part, followed by performing the test again to verify its functionality.

What was the outcome of replacing the ESI AM switch?

After replacing the ESI AM switch, the test showed that the large leak test passed, indicating a successful resolution of the issue.

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