AutoCodesCadillac – P0442 Cadillac

P0442 Cadillac Code - Evaporative Emission System Small Leak Detected

Quick Answer

The engine off natural vacuum test is the small leak detection diagnostic for the evaporative emission system. Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means
P0442 Cadillac indicates Evaporative Emission System Small Leak Detected.
Common causes
Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close.
Severity
Low - monitor the vehicle and repair when practical.
Can I drive?
The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 84,779
How popular is this code, among other codes? Medium
Table of contents Created and updated by William Orellana on Jun 27, 2022
💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0442 Cadillac Description

The engine off natural vacuum test is the small leak detection diagnostic for the evaporative emission system. This diagnostic tests the Evaporative Emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. The heat from the exhaust system is transferred into the fuel tank while the vehicle is operating. Prior to running this test fuel volatility is analyzed and then factored into this test. When the vehicle is turned OFF and the EVAP system has sealed a change in the fuel tank vapor temperature occurs which results in a corresponding pressure change in the fuel tank vapor space. This change is monitored by the Engine Control Module (ECM) using the Fuel Tank Pressure (FTP) sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a leak in the EVAP system that is greater than a calibrated amount.
OBDII Code P0442 Cadillac - Evaporative Emission System Small Leak Detected - AutoCodes.com
P0442 Cadillac Code - Evaporative Emission System Small Leak Detected

What are the Possible Causes of the DTC P0442 Cadillac?

  • Missing or loose fuel cap
  • Incorrect fuel filler cap used
  • Fuel filler cap remains open or fails to close
  • Foreign matter caught in fuel filler cap
  • Leaking EVAP Canister
  • Leaking EVAP System Hose
  • Leaking Fuel Tank
  • Faulty Fuel Tank Pressure Sensor

How to Fix the DTC P0442 Cadillac?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0442 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0442 Cadillac code?

Need more information on how to fix the P0442 Cadillac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0442 Cadillac code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0442 Cadillac Code

1. What does the OBDII code P0442 Cadillac indicate?

The code P0442 indicates that the Evaporative Emission System has detected a small leak.

2. What are the common symptoms of a P0442 code in a Cadillac?

Common symptoms include the check engine light coming on, a slight decrease in fuel efficiency, and the smell of gasoline near the vehicle.

3. What are the possible causes of a P0442 code in a Cadillac?

Possible causes include a loose or damaged gas cap, a cracked or damaged EVAP hose, a faulty EVAP canister, or a leak in the EVAP system.

4. How can I diagnose a P0442 code in my Cadillac?

Diagnosing a P0442 code typically involves checking the gas cap for tightness, inspecting the EVAP system for visible damage or leaks, and using a smoke machine to pinpoint the exact location of the leak.

5. Can a loose gas cap trigger a P0442 code in a Cadillac?

Yes, a loose or improperly sealed gas cap is a common cause of the P0442 code. Make sure to tighten the gas cap securely after refueling.

6. How serious is a P0442 code in a Cadillac?

While a P0442 code is not a severe issue that affects immediate drivability, it should be addressed promptly to prevent potential fuel system problems and to ensure the vehicle passes emissions tests.

7. How can I repair a P0442 code in my Cadillac?

Repairing a P0442 code may involve tightening or replacing the gas cap, repairing or replacing damaged EVAP system components, or clearing the EVAP system of any obstructions.

8. Can I drive my Cadillac with a P0442 code?

You can drive your Cadillac with a P0442 code, but it is advisable to address the issue as soon as possible to prevent further damage and to ensure the vehicle's emission system functions properly.

9. How much does it typically cost to repair a P0442 code in a Cadillac?

The cost of repairing a P0442 code can vary depending on the specific cause of the issue. Costs may range from a simple gas cap replacement to more extensive repairs involving EVAP system components.

10. Will a P0442 code reset itself in a Cadillac?

If the underlying issue causing the P0442 code is not resolved, the code may temporarily clear but is likely to reappear. It is recommended to diagnose and repair the problem to prevent ongoing check engine light alerts.

Discuss the causes and fixes for P0442 Cadillac OBDII Code

  • My engine light is on and fuel needle don't work.the codes says 442.

  • You probably have to replace the fuel level sensor inside the fuel tank.

  • I replaced the fuel level sensor and reconnected the battery and my fuel needle worked for about 3 minutes then it went back to empty mark were it stayed

  • I replaced the fuel level sensor and reconnected the battery and my fuel needle worked for about 3 minutes then it went back to empty mark were it stayed

  • I've replaced my gas cap. But my check engine light is still on. What's the next easiest step to solving this issue?

  • What model and year is your Cadillac?

  • 2008 escalade

  • There is a factory service bulletin for that code. I just posted a video above with the instruction on how to fix the problem, unfortunately the repair is not that simple.

  • 2011 cadillac srx has code p0442. Already replaced fuel cap with oem cap and also had the purge valve replaced. Code keeps reappearing....

  • There are some test that needs to be done to determine exactly what the problem is, but according to national database base of repairs for your vehicle, the most likely cause for the code is the purge valve, since you have already replace the purge valve, the second most common thing is the EVAP Canister Vent Solenoid.

  • My fuel cap was loose so I tightened it. How long would it take for he engine light to go off?

  • I have a 14 XTS TT. Has P0442 code. This car doesn't have a gas cap. 98k miles. Not sure what to look for.

  • The P0442 code means that there is an small EVAP system leak. According to a national database of repairs for your model and year, the most likely cause of the problem is the EAVP Purge Solenoid Valve.

    LF3

    Image

    Click here to enlarge image

    Or

    LFX

    Image

    Click here to enlarge image

  • 2006 dts cadillac code PO 0442 Replaced original gas cap reset & light came back on.

  • The Gas Cap is by far the most common problem for the P0442 code, if that didn't fixed the problem, then your next step is having a mechanic use a smog machine to detect the small leak. Unfortunately, finding a small EVAP leak could be difficult, but with a smog machine could help the mechanic find the leak in less time.

AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play