2010 Cadillac CTS Sedan AWD V6-3.6L Page 1407
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Catalytic Converter Replacement - Left Side (LLT) (See: Engine, Cooling and Exhaust/Exhaust System/Catalytic Converter/Service and
Repair/Catalytic Converter Replacement - Left Side)Catalytic Converter Replacement - Left Side (LSA) (See: Engine, Cooling and
Exhaust/Exhaust System/Catalytic Converter/Service and Repair/Catalytic Converter Replacement - Left Side)Catalytic Converter
Replacement - Left Side (LF1) (See: Engine, Cooling and Exhaust/Exhaust System/Catalytic Converter/Service and Repair/Catalytic
Converter Replacement - Left Side)
* Catalytic Converter Replacement - Right Side (LLT) (See: Engine, Cooling and Exhaust/Exhaust System/Catalytic Converter/Service and
Repair/Catalytic Converter Replacement - Right Side)Catalytic Converter Replacement - Right Side (LSA) (See: Engine, Cooling and
Exhaust/Exhaust System/Catalytic Converter/Service and Repair/Catalytic Converter Replacement - Right Side)Catalytic Converter
Replacement - Right Side (LF1) (See: Engine, Cooling and Exhaust/Exhaust System/Catalytic Converter/Service and Repair/Catalytic
Converter Replacement - Right Side)
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 V.
* The barometric pressure (BARO) is greater than 74 kPa.
* No fuel filling during the EONV test period.
* The fuel level is between 15-85 %.
* The start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) are between 0-40掳C (32-104掳F).
* The barometric pressure (BARO) is more than 74 kPa.
* The engine run time before engine shut-off was greater than 10 min.
* 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掳C (32-93掳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 min 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 hours
Conditions for Setting the DTC
* The ECM detects a leak in the EVAP system that is greater than a calibrated amount.
* The ECM must complete several EONV tests before the diagnostic can turn the MIL on or off.
Action Taken When the DTC Sets
DTC P0442 is a Type A DTC.
