2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2067

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2067

Canister/Canister Vent Valve/Service and Repair/Evaporative Emission Canister Vent Solenoid Valve Replacement (2500 Series))

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P0446

DTC P0446

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 P0446

- Evaporative Emissions (EVAP) Vent System Performance

Typical Scan Tool Data

Circuit/System Description

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to

be developed in the EVAP system. With the purge valve open and the canister vent valve open, if the EVAP system vacuum goes above a

calibrated threshold, the test will fail.

Conditions for Running the DTC

* DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451,

P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128,

P2135, P2138 are not set.

* The ignition voltage is between 11-18 volts.

* The barometric pressure (BARO) is more than 74 kPa.

* The fuel level is between 15-85 percent.

* The engine coolant temperature (ECT) is less than 35掳C (95掳F).

* The intake air temperature (IAT) is between 4-30掳C (39-86掳F).

* DTC P0446 runs once per cold start when the above conditions are met.

Conditions for Setting the DTC

* The fuel tank vacuum is greater than -12 inches H2O vacuum for 5 seconds.

OR

* The FTP is less than -2.5 inches H2O or more than +5 inches for 60 seconds after a cold start.

Action Taken When the DTC Sets

DTC P0446 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0446 is a Type B DTC.

Diagnostic Aids

* An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve

inlet, or a pinched vent hose. A blockage in the vent system may also cause a poor fuel fill condition.

* An EVAP canister filter that is restricted can cause this DTC to set.