Vehicle Application: 2000 Chevrolet Suburban 1500 5.3L 2003 Chevrolet Avalanche 1500 5.3L, GAS, Vin T
2001 Chevrolet Silverado 1500 4.3L, Vin W, Eng Cfg V6 2003 Chevrolet Silverado 1500 5.3L, GAS, Vin T, Eng Cfg V8
2002 Chevrolet Silverado 1500 5.3L, GAS, Vin T, Eng Cfg V8
Customer Concern: Repeat P0446. The updated vent kit has been installed.
Tests/Procedures: 1. Install the scan tool and monitor the fuel tank pressure sensor value to be approximately 1.5 volts and/or 0 inches of water vacuum (+-0.5" H2O).
2. Run the engine at a hot curb idle and view the purge solenoid command. Increase engine speed and the purge solenoid % will increase.
3. Verify the tank pressure sensor value does not go up (a slight increase of approximately 0.5 volts/1" H2O is normal).
4. If the value increases, disconnect the large hose on the canister (this is the vent hose). If the value drops, check for the filter to be plugged or incorrect vent assembly installation.
5. If the value continues to rise, replace the canister.
Potential Causes: Canister
Vent Control Solenoid
Tech Tips: Refer to bulletin #02-06-04-037D - (04/16/2008) for the updated vent kit information.
Diagnostic Codes: P0446
P0446 EVAP Vent System PerformancePossible Causes Setting Conditions
EVAP vent fresh air hose is clogged, kinked or restricted
EVAP Vent solenoid is contaminated, damaged or has failed
EVAP Canister plugged or severely restricted
Fuel Cap or EVAP Service Port leaking
Fuel vapor lines or purge lines damaged or leaking
FTP sensor is out-of-calibration, damaged or "skewed"
PCM has failed
DTC P0106, P0107, P0108, P0112, P0113, P0116-P0118, P0125, P0440-P0453, P1111-P1115, P1120, P1220 and P1221 not set; engine running, ECT and IAT sensors from 39-86ºF and within 16ºF at startup, BARO over 75 kPa, fuel level from 15-85%, vehicle driven to a speed of less than 75 mph, and the PCM detected the fuel tank pressure sensor indicated less than -10 inches H2O for 20 seconds.
This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)