Have I diagnosed bad tank pressure sensor correctly?

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Topic author
rlyoung
I am smitten with my van
Posts: 34
Joined: Wed May 18, 2016 9:01 am

Have I diagnosed bad tank pressure sensor correctly?

Post by rlyoung »

Hope I got the right section.

Over time I've been looking at the potential causes for a P0446 EVAP code. I've replaced the gas cap, and bench tested the vent valve which it appears to be fine. Yesterday I pulled the fuel tank pressure sensor, but left it still wired up. The reference wire had its 5 volts, and the signal wire had 4.78 volts in free air. I applied the slightest vacuum (5 in.-Hg) and then equal positive pressure to the sensor with a mityvac and the voltage on the signal wire to ground did not ever budge from 4.78. It appears to be stuck there. Unless I am misunderstanding how it works, it must be bad? Thanks in advance for any help.

2001 AWD, 212K miles.

AstroWill
I finally get the smurf thing
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Re: Have I diagnosed bad tank pressure sensor correctly?

Post by AstroWill »

No change on the signal wire with pressure change = bad sensor.

Topic author
rlyoung
I am smitten with my van
Posts: 34
Joined: Wed May 18, 2016 9:01 am

Re: Have I diagnosed bad tank pressure sensor correctly?

Post by rlyoung »

Excellent. Thanks for answering.
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