Hey folks. Thought I’d run this by everyone and see if I missed anything. I have been chasing the P0455 for a while. Here are the things I have replaced:

1. Fuel pump assembly.
2. Fuel filler tube (cap to tank).
3. Fuel cap (oem).
4. Fuel canister purge valve.
5. Evaporator valve

I have also pulled the charcoal canister and blown in the openings )all free flowing). No charcoal dust coming out. No apparent cracks (that my eyes can see).

i don’t have a compressor so I can’t blow out the lines but I have no problems with fill ups so I don’t expect a blockage.

Ideas?

I’m fresh out. It runs really well, and I have no other codes thrown.

 

Do you have a scanner to monitor the tank pressure?

Need to see if vacuum is being applied and how long it takes to leak down

My purge solenoid was bad and I was getting the P0455, I replaced it with a off brand and it did the same thing, I then replaced it with a AC Delco and have had not issues since.

Without a scanner or the ability to see the tank pressure it will be very hard to isolate the issue

 

I see.. I have a bluedriver scanner. I know it reads live data but unsure of tank pressure. I’m going out to check. Thank you for the feedback. Would you by any chance know how to check? Any kind of procedure?

ill check back in a few. I need to put the canister back on and hook the lines up.

 

First thing is to monitor the tank pressure while driving, if the purge solenoid indicates open but is not or the line is plugged then the ECM thinks that vacuum is being applied and is looking for the tank pressure to drop into a vacuum. If the tank does not drop into a vacuum then the ECM thinks there is a large leak. The purge solenoid can be stuck closed or the line to the tank from the purge solenoid can be plugged. First set your scanner to monitor the tank pressure and the purge and vent solenoid positions if possible and drive around for a bit watching if the tank is pulled down into a slight vacuum.

 

Circuit/System Description

The ECM tests the Evaporative Emission (EVAP) System for a large leak or restrictions to the purge path in the EVAP system. When the enabling criteria has been met the ECM commands the EVAP canister vent solenoid valve ON and the EVAP canister purge solenoid valve ON, allowing vacuum into the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time.

 

Thanks I’ll give the scanner a try and see if it can read the tank pressure. I know the line from the valve to the canister is ok... I can blow in that one and there is no restriction.

Ill let you know tomorrow.

 

I sent an email to bluedriver. Looks like I’m out of luck:

Thanks for contacting us! Unfortunately, fuel tank pressure is not a standard OBDII live data PID and is not currently supported by BlueDriver. We will be working on ‘enhanced’ or manufacturer live data for your vehicle in the future, but there aren’t currently any firm timelines for when this will be complete.


I guess I’ll just put it back together and keep looking. I pulled the box out for the evap canister valve and it was ac Delco...

 

I pulled this off my scanner yesterday.

www.BlueDriver.com
VIN: DECODED:
Model Year: Make: Model: Trim Level:
P0455 Repair Report
5GRGN23U95H133695
2005 Hummer H2 (Base)
2005 Hummer H2
Base
P0455 CODE DEFINITION:
• Evaporative Emission (EVAP) System
8 POSSIBLE CAUSES:
• ECM has failed
• Fuel filler cap is very loose, missing or the wrong part
• Fuel tank pressure sensor is damaged, disconnected or it failed • Fuel tank vapor line(s) is clogged, damaged or disconnected
• Fuel tank, fuel filler neck or fuel sending unit 'O' ring is leaking
• Purge solenoid is not opening (it may be damaged or sticking)
• Purge valve vapor line is clogged, damaged, or disconnected
• Vent solenoid is not closing (it may be damaged or sticking)
3 TOP REPORTED FIXES:
• Replaced Evaporative Emissions (EVAP) Canister Vent Solenoid/Valve
• Replaced Evaporative Emissions (EVAP) Canister Purge Solenoid/Valve • Replaced Fuel Filler Cap
13 FREQUENTLY REPORTED FIXES:
Disclaimer:
The Possible Causes outlined above may or may not be the cause of your vehicle trouble code(s) being triggered. The Reported Fixes listed are suggestions only, and a fix is not guaranteed by performing any of the above potential solutions. The trouble code summary data may help you pinpoint the type of repair facility that should be consulted. It is strongly recommended that you consult with a knowledgeable professional repair facility for proper diagnosis and repair of trouble code issues. This information is provided without warranty and is subject to the Terms of Use posted at Lemur Vehicle Monitors - BlueDriver EULA. Reproduction of this information or any portion thereof constitutes infringement of copyright.
© Copyright 2019 Page 1

www.BlueDriver.com
VIN: DECODED:
Model Year: Make: Model: Trim Level:
P0455 Repair Report
5GRGN23U95H133695
2005 Hummer H2 (Base)
2005 Hummer H2
Base
13 FREQUENTLY REPORTED FIXES: (Continued)
• Replaced Charcoal Canister
• Replaced Fuel Tank Pressure (FTP) Sensor
• Replaced Vent Control Valve
• Replaced Fuel Pump / Sending Unit Assembly
• Replaced Fuel Tank Sending Unit O-Ring
• Replaced Evaporative Emission (EVAP) System Hose(s)/Line(s)
• Repaired Evaporative Emissions (EVAP) Canister Vent Solenoid/Valve Wiring • Replaced Fuel Filler Neck
• Replaced Powertrain Control Module (PCM)
• Replaced Canister Vent (CANV) Solenoid w/P0446
• Tightened Fuel Filler Cap
• Installed Fuel Filler Cap
• Replaced Fuel Tank
25 OTHER REPORTED FIXES:
• Repositioned Canister Vent Filter
• Installed Canister Vent Filter
• Replaced Charcoal Canister Hose(s)
• Repaired Charcoal Canister Hose(s)
• Replaced Crankshaft Position (CKP) Sensor w/P0300, P0352
• Repaired Crankshaft Position (CKP) Sensor Wiring w/P0300, P0352
Disclaimer:
The Possible Causes outlined above may or may not be the cause of your vehicle trouble code(s) being triggered. The Reported Fixes listed are suggestions only, and a fix is not guaranteed by performing any of the above potential solutions. The trouble code summary data may help you pinpoint the type of repair facility that should be consulted. It is strongly recommended that you consult with a knowledgeable professional repair facility for proper diagnosis and repair of trouble code issues. This information is provided without warranty and is subject to the Terms of Use posted at Lemur Vehicle Monitors - BlueDriver EULA. Reproduction of this information or any portion thereof constitutes infringement of copyright.
© Copyright 2019 Page 2

www.BlueDriver.com
VIN: DECODED:
Model Year: Make: Model: Trim Level:
P0455 Repair Report
5GRGN23U95H133695
2005 Hummer H2 (Base)
2005 Hummer H2
Base
25 OTHER REPORTED FIXES: (Continued)
• Repaired Engine Wiring Harness w/P0300, P0352
• Repaired EVAP Canister Vent Hose
• Repaired Evaporative Emission (EVAP) System Hose(s)/Line(s) w/P0496 • Repositioned Evaporative Emissions (EVAP) Canister Vent Solenoid/Valve • Tightened Evaporative Emissions (EVAP) Canister Vent Solenoid/Valve
• Lubricated Evaporative Emissions (EVAP) Canister Vent Solenoid/Valve
• Cleaned Evaporative Emissions (EVAP) Canister Vent Solenoid/Valve
• Replaced Exhaust Gas Recirculation (EGR) Valve
• Replaced Exhaust Manifold w/P0300, P0352
• Repaired Fuel Filler Neck
• Repaired Fuel Injector Wiring w/P0102, P0200, P0300...
• Replaced Fuel Pump Module Seal
• Repaired Ignition Coil Wiring w/P0300, P0352
• Replaced Ignition Coil Wiring w/P0300, P0352
• Replaced Intake Manifold w/P0300, P0352
• Replaced Oxygen (O2) Sensor(s)
• Replaced Spark Plug Wire(s) w/P0300, P0352
• Replaced Spark Plug(s) w/P0300, P0352
• Cleaned Throttle Body
Disclaimer:
The Possible Causes outlined above may or may not be the cause of your vehicle trouble code(s) being triggered. The Reported Fixes listed are suggestions only, and a fix is not guaranteed by performing any of the above potential solutions. The trouble code summary data may help you pinpoint the type of repair facility that should be consulted. It is strongly recommended that you consult with a knowledgeable professional repair facility for proper diagnosis and repair of trouble code issues. This information is provided without warranty and is subject to the Terms of Use posted at Lemur Vehicle Monitors - BlueDriver EULA. Reproduction of this information or any portion thereof constitutes infringement of copyright.
© Copyright 2019 Page 3

 

without the ability to see the tank pressure and or command the solenoids to open and close diagnosing this issue is rather difficult

 

Yeah I can understand why. What kind of low cost scanner can I get to see the things I need to see? I just drive it. No cel yet but it takes a few days.