fxmfrank Posted December 7, 2011 Report Share Posted December 7, 2011 I've had a P0446 code on my 2002 Deville for several weeks now. The car runs fine but I'm sure I won't pass Massachusetts state inspection. I plan on replacing the evap canister solenoid and if necessary the evap canister as well. I know this is a foolish question for a DIY guy but I'm not sure where the evap canister is located. I'm sure it's near the gas tank. Can anyone help me. I picture would be helpful. Also, any tips on proceeding with this job. Thanks everyone. Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 7, 2011 Report Share Posted December 7, 2011 Welcome aboard. Are you getting any other codes? I am going to post some info for you, don't parts replace, try to figure it out first. Info -Evaporative Emissions DTC P0440, P0441, P0442, P0446 #00-06-04-011A - (Oct 4,2001) EvaporativeEmissions DTC P0440, P0441, P0442, P0446 1996-2002 Passenger Cars and Trucks With Enhanced Evaporative EmissionsEngines Except 1998-1999 Chevrolet Prizm This bulletin is being revised toadd model years and diagnostic enhancements. Please discard Corporate BulletinNumber 00-06-04-011 (Section 6-Engine). Enhanced Evaporative Emissionstesting of 1996 and newer vehicles with enhanced evaporative emissions requiresmore stringent testing of the fuel system for evaporative emissions leaks.Vehicles with this system use an on-board diagnostic module (i.e. PowertrainControl Module (PCM) or Vehicle Control Module (VCM) as the controller. For thebalance of this bulletin, we will refer to either of these components as amodule. Enhanced Evaporative Emission testsmay be performed by the vehicle's module when specific conditions are met.These conditions are determined by the calibration within the module. Thesecalibrations are vehicle platform and engine family specific. When the key is turned to the startor run position, the module checks the output of various sensors on the vehicleto determine when and if the Evaporative Emissions tests should be run. Referto Engine Controls sub-section of the appropriate Service Manual for specificDTC information. Some of the most widely usedparameters are listed below: The Barometric Pressure (BARO) is greater than a specified kPa (psi). The system voltage is between 10 and 18 volts. The intake air temperature (IAT) is within specified temperature values. The engine coolant temperature (ECT) is within specified temperature values. The ECT and IAT are within specified temperatures of each other when the vehicle engine was started. The fuel level sensor indicates the fuel level is greater than a specified % of empty and less than a specified % of full. (For a 76 L (20 gal) fuel tank, a fuel level of more than 11 L (3 gal) but less than 64 L (17 gal) or as specified in the calibration). Some platforms such as the Alero and Grand Am, use a miles driven check as well. For the ECT and IAT to be within thespecified temperatures of each other at the time of engine start-up, the enginewill have to be in the non-running condition for a long enough period of timefor the engine coolant temperature to drop from its normal operatingtemperature down to roughly 30°C (90°F). This could take several hours. When the control module determinesthat the above conditions are met, the module tests for a leak in the EVAPsystem by: Electrically closing the vent valve in order to seal the system. Electrically opening the purge valve which allows the running engine to draw a vacuum on the fuel tank. The module then closes the purge valve, resealing the system. The module then monitors the fuel tank pressure sensor and determines: [*]If vacuum was achieved. [*]If a leak is present, how large the leak is. [*]If vacuum was not achieved. If one of the above tests fails, the module remembers that the system failed the test. <li>If the module sees a failure of the EVAP test for two consecutive tests, the module will set a trouble code for EVAP leak (DTCs P0440, P0442, or P0446). Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 7, 2011 Report Share Posted December 7, 2011 My post above was a Bulletin, this is a Diagnostic specifically for the P0446 code, it seems to be leading to a restriction DTC P0446 [/url] System Description This DTC tests the evaporativeemission (EVAP) system for a restricted or blocked EVAP vent path. The controlmodule commands the EVAP canister purge solenoid Open and the EVAP canistervent solenoid Closed. This allows vacuum to be applied to the EVAP system. Oncea calibrated vacuum level has been reached, the control module commands theEVAP canister purge solenoid Closed and the EVAP canister vent solenoid Open.The control module monitors the fuel tank pressure (FTP) sensor for a decreasein vacuum. If the vacuum does not decrease to near 0 inches H2O in a calibratedtime, this DTC sets. The following table illustrates therelationship between the ON and OFF states, and the Open or Closed states ofthe EVAP canister purge and vent valves. (see table below that I posted as an attachment, it did not post good as text, so I converted it to a photo) Conditions for Running the DTC DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0440, P0442, P0443, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121, P1122 are not set. The ignition voltage is between 10-18 volts. The barometric pressure (BARO) is more than 75 kPa. The fuel level is between 15-85 percent. The start-up engine coolant temperature (ECT) is less 30°C (86°F). The intake air temperature (IAT) is between 4-30°C (39-86°F). The start-up ECT and IAT are within 9°C (16°F) of each other. The vehicle speed sensor (VSS) is less than 121 km/h (75 mph). Conditions for Setting the DTC The FTP does not increase acalibrated amount during a calibrated period of time. Action Taken When the DTC Sets The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. Conditions for Clearing the MIL/DTC The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. A current DTC, Last Test Failed, clears when the diagnostic runs and passes. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. Clear the MIL and the DTC with a scan tool. <a href=" http://127.0.0.1:9001/servlets/BlobShtml?ShtmlFile=794003&psdid=264&evc=sm#ss3-794003"> Diagnostic Aids An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP vent solenoid inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 7, 2011 Report Share Posted December 7, 2011 Here are photos that show EVAP details, the photos have descriptions see attachments Use the numbers from the text below to identify the components in the EVAP purge solenoid valve picture: Disconnect the evaporative emission (EVAP) canister purge valve electrical connector (5). Disconnect the EVAP purge pipe (4) from the EVAP canister purge valve (3) Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
fxmfrank Posted December 9, 2011 Author Report Share Posted December 9, 2011 Thanks for your response. This is very helpful. Again, I'm not a mechanic but I try to do as much as I can on my own. Can't afford visiting the dealer for all problems. I have one further question. Looking at the diagrams it looks like there are three major components in the EVAP system. The EVAP Canister and the EVAP Canister Solenoid which are located together near the gas tank. The other component, EVAP Purge Solenoid which is in the engine compartment. Is this correct? The diagram shows disconnecting the electrical connector and the vacuum line from the EVAP Purge Solenoid. Is this something I want to do first to check blockage? Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 9, 2011 Report Share Posted December 9, 2011 You are correct about the components locations I am not sure how to diagnose the problem, but I would start by checking for kinked and damaged lines from road debris, jacking, etc I would think if you could isolate the lines using compressed air to see if they are clear would be helpful. Keep in mind that you are working around fumes (There was a warning in the manual) Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
fxmfrank Posted December 11, 2011 Author Report Share Posted December 11, 2011 Thank you very much for your help! I'll let you know how I make out. Link to comment Share on other sites More sharing options...
fxmfrank Posted December 22, 2011 Author Report Share Posted December 22, 2011 Thank you very much for your help! I'll let you know how I make out. Well I still have the Code P0446 after replacing the EVAP Canister solenoid valve. I cleared the code and it stayed off for about 5 days then came back on. I checked several of the lines with no signs of cracks, kinks , etc. I suppose there are at least three more components that could be causing the problem code. The EVAP canister, the Evap sensing unit and the Evap purging valve. I was thinking of changing the Evap purging valve next because it works hand and hand with the Evap solenoid valve,when one is open the other is closed for the circuit to work correctly. Does this make sense? One other question: I have had a faulty level sending unit for a couple of years now. Always reads a full tank of gas, except when I turn on the ignition and the engine is not started. Is it possible that the DTC thinks there is too much gas in the tank and kicks on the code. Like I said the fuel gauge has not performed correctly for a long time whereas the P0446 code has only come on over the last 4 or 5 months. Any more help or suggestions would be greatly appreciated. Link to comment Share on other sites More sharing options...
Ranger Posted December 23, 2011 Report Share Posted December 23, 2011 Is it possible that the DTC thinks there is too much gas in the tank and kicks on the code. No, it's the fuel level sensor sending the wrong information. It has nothing to do with the EVAP code. Link to comment Share on other sites More sharing options...
fxmfrank Posted December 23, 2011 Author Report Share Posted December 23, 2011 Is it possible that the DTC thinks there is too much gas in the tank and kicks on the code. No, it's the fuel level sensor sending the wrong information. It has nothing to do with the EVAP code. Link to comment Share on other sites More sharing options...
fxmfrank Posted December 23, 2011 Author Report Share Posted December 23, 2011 Ya, I didn't think so but it's just one other thing. I appreciate your input and any other comments you might have. I will replace the EVAP canister purge valve because its relatively inexpensive and easy to get at. Thanks everyone and Merry Christmas. Link to comment Share on other sites More sharing options...
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