Mechanics

CHEVY DTC/PO449

2007 Chevrolet Colorado

Computer problem
2007 Chevy Colorado 6 cyl Two Wheel Drive Automatic 44678 miles

VIN #1GCDS19E08813130633

Getting trouble code #'s PO449/449 pending/455 pending. The DTC giving me freeze frame info is PO449 (evap. Emission control system valve/solenoid malfunction). I have an Actron generic scanner and can read the codes and freeze frame data but don't have any diagnostic capabilities and need some suggestions based on the FF data below.
THROTTLE POSITION) 32.1
ENGINE RPM) 1475
LOAD VALUE) 48.2
MAP SENSOR) 60
AIR FLOW RATE) 20.33
COOLANT TEMP) 190
INTAKE AIR TEMP) 78
IGNITION TIMING ADVANCE) 30.0
BARO PRESSURE) 102
AMBIENT AIR TEMP) 75
COMM. SECONDARY AIR STATUS) ATMOS
CATALYST TEMP BANK1/SENSOR1) 1450
EVAP. VAPOR PRESSURE) 14.127 H20
SHORT TERM FUEL TRIM 1) 0.8
LTFT1) 0.0
STFT3) 32.8
LTFT3) 32.8
VEHICLE SPEED) 46
FUEL SYSTEM 1) CLOSED
FUEL SYSTEM 2) NA
ABSOLUTE LOAD VALUE) 38.0
RELATIVE THROTTLE POSITION) 18.4
COMMAND THROTTLE ACTUATOR CONTROL) 27.0
ABSOLUTE THROTTLE POSITION B) 31.7
ACCEL. PEDAL POSITION D) 27.8
ACCEL. PEDAL POSITION E) 13.7
COMMAND. EVAP PURGE) 95.6
COMMAND. EQUIVALENCE RATIO) 0.999
DISTANCE SINCE CODES CLEARED) 8,464 MI
WARMUPS SINCE CODES CLEARED) 65,450
FUEL LEVEL INPUT) 44.3
CONTROL MODULE VOLTAGE) 13.546
Avatar
Mtrdude
August 19, 2009.



P0449
Battery voltage is supplied to the EVAP canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF. The control module monitors the status of the driver.

1. With the ignition ON and the engine OFF, command the EVAP vent solenoid ON and OFF with a scan tool.
2. Listen for a click when the valve operates. Verify that both the ON, and the OFF states are commanded

Ignition OFF, disconnect the harness connector at the EVAP canister vent solenoid valve.
Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal A and ground.
If a test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the EVAP canister vent solenoid valve.
Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
Command the solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between commanded states.
If the test lamp is always ON, test the control circuit for a short to round. If the circuit tests normal, replace the control module.
If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the control module.
If all circuits test normal, replace the EVAP canister vent solenoid valve

BMRFIXIT
Aug 19, 2009.