check engine Codes P440 P441 P446

[craig_avalon]

Hi All,
I'm getting these check engine codes in Totoya Avalon 2000 model XLS.

Sometime, car does not start..Screeches after cranking.
If I pedal accelerator high, it starts.

Any clue, what could be going wrong?

Thanks
Craig

[csaxon]

TSB EGO13-03 (sep 29, 2003)MIL "ON" DTC po440,441 or 446. Bad Canister Closed Valve Vacuum Switching Valve ( CCV VSV). Affect '00-03 Avalon, Camry and Solara.
The tsb has 5 pages of tests to determine if the vsv is bad. Check the vacuum hoses around it etc.

Covered under 3yr 36000 mile warranty.

[maun]

Craig, I have the same codes. What was your fix?

Tks,
Norman Mau

[Brian R.]

Check the TSBs listed in the above posts.

Here's some general information about these codes:

P0440
The fuel tank pressure is atmospheric pressure after the vehicle is driven for 20 min (2 trip detection logic).

Possible Problems
Fuel tank cap incorrectly installed <= Most common
Fuel tank cap cracked or damaged (Toyota part only)
Bad vapor pressure sensor/circuit
Vacuum hose cracked, holed, blocked, damaged or disconnected
Hose or tube cracked, holed, damaged, or loose
Fuel tank/filler neck cracked, holed, or damaged
Charcoal canister cracked, holed, or damaged (collision)

In above description, check hoses between vapor pressur sensor and VSV for vapor pressure sensor and charcoal canister. Also, hose between charcoal canister and fuel tank.


P0441 and/or P0446

Possible Problems
Open or short in VSV circuit for vapor pressure sensor
VSV for vapor pressure sensor
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Vacuum hose cracks, hole, blocked, damaged or disconnected
Charcoal canister cracks, hole, or damaged

(P0446 is not normally associated with a loose or non-sealing gas cap. A loose or non-sealing gas cap triggers P0440)

1. Check the VSV connector for EVAP, VSV connector for vapor pressure sensor and vapor pressure sensor connector for looseness and disconnection

2. Check the vacuum hose between intake manifold and VSV for EVAP, VSV for EVAP and charcoal canister, charcoal canister and VSV for vapor pressure sensor, and VSV for vapor pressure sensor and vapor pressure sensor. Check these hoses for correct connection, looseness, cracks, holes, damage, and blockage.

3. Check voltage between terminals VC and E2 of ECM connector (4.5-5.5 V). (replace ECM if faulty)

4. Check voltages between terminals PTNK and E2 of ECM connector while applying vacuum to vapor pressure sensor (2.9-3.7 V).

If faulty, check for open and short in harness and connector between vapor pressure sensor and ECM. If ok at this point, replace vapor pressure sensor.

If voltage above is ok, Check VSV for EVAP. When ECM terminal EVP is grounded (ignition "ON"), Air should flow in pipe E (inboard on tube) on VSV and out F (outboard on tube) on VSV (Don't use high pressure air for this test). When EVP is not grounded, air does not flow in E and out F.

5. Check operation of VSV for EVAP. Remove VSV from engine. Check that there is continuity between the two terminals (30-34 ohms). If there is no continuity, replace VSV for EVAP.

Check that there is no continuity between either terminal and body. If there is continuity, replace VSV for EVAP.

Check that air does not flow from inner port (E) to outboard port (F).

Check that air flows from port E to F when you apply battery voltage across terminals. If no air flows, replace VSV for EVAP.

6. Check the vacuum hose between intake manifold and VSV for EVAP, and VSV for EVAP and charcoal canister. Check as above.

7. Check for open or short in harness and connector between EFI main-relay and VSV for EVAP and ECM. If faulty, repair or replace harness or connector. If ok, check and replace ECM.

8. Check VSV for vapor pressure sensor. When ECM terminal TPC is grounded (ignition "ON"), Air should flow in pipe E (inboard on tube) on VSV and out F (outboard on tube) on VSV. When TPC is not grounded, air flows out G (outside of connector).

If ok, check and replace charcoal canister.

If not functioning correctly, check function of VSV for vapor pressure sensor. Remove from engine.
Check that there is continuity between the terminals (33-39 ohms). Replace the VSV if there is no continuity.

Check that air flows from port E (inboard in tube) to port G (side of connector).

Check that air flows from port E to port F (outboard in tube) when battery voltage is applied across terminals. Replace VSV if function is incorrect.

9. If good, Check the vacuum hose between charcoal canister and VSV for vapor pressure sensor, and vapor pressure sensor and VSV for vapor pressure sensor - check as above.

11. Check for open and short in harness and connector between EFI main replay and VSV for vapor pressure sensor and ECM.

[maun]

Thanks for the information Brian.

[Brian R.]

You're welcome. There's alot of information related to Avalons in the FAQ thread in the Camry forum.

[sferguson]

I was having same codes show up. After replacing sensors, cap, & checking hoses from front to rear I found a dirt dobber had built a nest in the large hose that vents the canister near the left rear where filler hose is located.I also found the small vacum line stopped up where it goes into the large vent hose. After cleaning I placed a screen over end of large vent hose. I can even fill the gas tank as fast as the pump will pump, before cleaning I could not fill tank without pump kicking off.

[kruiser]

Hi all,

It was great that I found this thread. I have the same 3 codes in my 2003 Avalon. Have already replace the charcoal canister and the gas cap, all toyota parts. The codes came back in a day.

The information posted so far is very informative but I'm wondering if I can get some help on the following:

1) where to see the actual TSB EGO13-03.

2) If anybody has a diagram of the Evap system, I want to make sure the hoses are connected correctly to the canister and then locate the VSV valve.

Any help would be greatly appreciated, thanks!

[Brian R.]

There should be a hose diagram under the hood on a decal.

In the Camry forum, there's a sticky post that has links to many maintenance manuals. There are diagrams and VSV locations there for your engine. Download http://www.turbotoyota.com/FSMs/2001...300%20FSMs.zip - unzip and check out the Evap system in there.

[Brian R.]

For example - from the above link:

[Brian R.]