On a 2003 Buick Century, I am not getting enough voltage/amps to pull in the vent valve on the evap system. I'm suspeciting a bad relay. Where is it?

Asked by Feb 08, 2017 at 09:29 AM about the 2003 Buick Century Sedan FWD

Question type: Maintenance & Repair

I see voltage at the vent valve solenoid but it is not enough to pull in the solenoid to close the valve when the ignition is on. It closes fine if wired to the battery. I'm getting the P0446 code. Is there a relay that may be bad somewhere on the car?  Is this signal routed thru the Purge valve?

3 Answers

85,365

If you see voltage, but it is low, there is more than likely a bad connection, or the wire strands are breaking, usually at the plugins. Also a bad ground could be a cause. There is power so I don't think it is a relay. You can check your fuse boxes for any emissions related fuses or relays.

I've been doing a little research here. Looks like it just takes a hot power signal thru the 30A ECS system fuse to the vent valve solenoid, the PCM grounds it when the Ignition is on to cause the valve to close. There is anoter fuse between the vent valve and PCM which I need to check under the hood, but no control relays, as the PCM controls the switching. Your recommendation for broken wires seems the most plausible if the fuse is not corroded/bad. I will check that out. Thanks

85,365

Keep me informed, always like to know...

Your Answer:

Century

Looking for a Used Century in your area?

CarGurus has 530 nationwide Century listings starting at $1,995.

ZIP:

Buick Century Experts

  • #1
    John Saffrahn
    Reputation
    1,050
  • #2
    Tom Demyan
    Reputation
    940
  • #3
    John Pate
    Reputation
    680
View All

Related Models For Sale

Used Buick Regal
88 Great Deals out of 3,659 listings starting at $1,995
Used Buick LeSabre
1,348 listings
Used Chevrolet Impala
513 Great Deals out of 25,945 listings starting at $995
Used Buick Park Avenue
3 Great Deals out of 283 listings starting at $2,000
Used Toyota Camry
858 Great Deals out of 70,625 listings starting at $1,300
Used Chevrolet Malibu
604 Great Deals out of 50,816 listings starting at $600
Used Honda Accord
682 Great Deals out of 101,646 listings starting at $999
Used Toyota Corolla
672 Great Deals out of 63,571 listings starting at $1,499
Used Honda Civic
486 Great Deals out of 44,345 listings starting at $1,150
Used Ford Taurus
203 Great Deals out of 16,068 listings starting at $600
Used Ford Mustang
310 Great Deals out of 39,695 listings starting at $1,312
Used Chevrolet Silverado 1500
1,780 Great Deals out of 154,899 listings starting at $1,700

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.