P0442 GMC - Evaporative Emission Control System Leak Detected Small Leak
- 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
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
The P0442 code means that the control module has detected a small leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the most common cause that triggers the P0442 code.
When is the code detected?
Malfunction is detected when EVAP control system has a leak, EVAP control system does not operate properly.
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors
P0442 GMC Description
The Powertrain Control Module (PCM) tests the Evaporative Emission (EVAP) system for the following conditions:
- Large and small leaks
- Excess vacuum
- Purge flow during non-commanded conditions
- Fuel Level and Fuel Pressure sensor faults
- EVAP Purge and Vent Valve faults
The PCM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. The PCM commands both the EVAP Purge Solenoid and the EVAP Vent Valve ON when the conditions are met in order to apply an engine vacuum to the EVAP system. The PCM commands the EVAP Purge Solenoid OFF once the system has reached a predetermined level of vacuum. This test verifies if a vacuum can be achieved in the EVAP system. Failure to develop a vacuum may be caused by a large leak or a restriction.
Need more help?
Do you need more help with the P0442 GMC code? ask a question to our users or search the top hand picked automotive forums for more information
GMC Technical Service Bulletins for P0442 code
2003 GMC SIERRA CLASSIC Engine And Engine Cooling:engine Details
2003 GMC SIERRA CLASSIC Engine And Engine Cooling:exhaust System:emission Control Details
2003 GMC SIERRA CLASSIC Fuel System, Gasoline:storage:tank Assembly:filler Pipe And Cap Details
2004 GMC SIERRA CLASSIC Engine And Engine Cooling:engine Details
2004 GMC SIERRA CLASSIC Engine And Engine Cooling:exhaust System:emission Control Details
Repair Shops Around Your Area
Need parts to fix this code? Search hundreds of stores at the same time and compare prices
Help us improve Engine-Codes.com. Leave a comment below or tell us if the information above help you fix the code. What are symptoms is your vehicle for the P0442 GMC code?
Have you replaced any parts?
Any information is appreciated. Thanks