* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control
Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (2500 Series) (See: Powertrain
Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)
* Exhaust Leakage (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Exhaust Leakage)
* Restricted Exhaust (See: Engine, Cooling and Exhaust/Exhaust System/Testing and Inspection/Restricted Exhaust)
Repair Verification
1. Verify that no other DTCs are set.
锟斤拷If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic
Trouble Code (DTC) List - Vehicle).
2. Operate the vehicle within the Conditions for Running the DTC while observing the scan tool Catalyst Monitor Not At Idle Test Conditions
Met parameter. The parameter will change to Yes when the OFF Idle Conditions have been met.
锟斤拷If not the specified value, operate the vehicle within the OFF Idle Conditions.
3. When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
4. Apply the service brake.
5. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.
6. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.
7. When the test has completed, the Catalyst Monitor Test Counter Bank 1 or Bank 2 parameter will increment by one and the Catalyst Monitor
Test Result Bank 1 or Bank 2 parameter will indicate Pass, Fail, or No Decision.
锟斤拷If no decision has been made, repeat steps 2-6 until the Test Result parameter indicates a Pass or Fail.
P0442
DTC P0442
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0442
- Evaporative Emission (EVAP) System Small Leak Detected
Circuit/System Description
The engine off natural vacuum (EONV) 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. Heat from the exhaust system
is transferred into the fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is 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 ECM
using the fuel tank pressure sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system.
Conditions for Running the DTC
* DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0222, P0223, P0443, P0446, P0449,
P0451, P0452, P0453, P0454, P0455, P0461, P0462, P0463, P0464, P0496, P0502, P0503, P0608, P0641, P0651, P1516, P2101, P2119,
P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
* The ignition 1 voltage is between 10-16 volts.
* The barometric pressure (BARO) is greater than 74 kPa.
* No fuel filling during the EONV test period.
* The fuel level is between 15-85 percent.
* The start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) are between 0-40锟斤拷C (32-104锟斤拷F).
* The barometric pressure (BARO) is more than 74 kPa.
* The engine run time before engine shut-off was greater than 10 minutes.
* The drive distance before engine shut-off was more than 5 kilometers (3.1 miles).
* The ignition is OFF.
* The ambient air temperature at the end of the drive cycle is between 0-32锟斤拷C (32-93锟斤拷F).
* DTC P0442 runs once per drive cycle during the hot soak period after the ignition is turned OFF and may require up to 45 minutes to
complete. The controller will not make more than 2 test attempts per day. The time since the last completed EONV test must be at least 17
