2001 honda accord lx v6 sedan 190,000 km

DTC 1456 code

i troubleshoot with a honda service manual following every step up to the
EVAP bypass solenoid valve test.

the procedure is to apply vacuum on the EVAP two way valve and have the computer (A3) blue wire grounded and ignition switch on

this procedure activate the EVAP bypass solenoid and release the vacuum

my question is how much vacuum should i apply to perform this test ( inch Hg )


i do this test and it is ok up to (13 inch Hg ) it release the vacuum


with more than (13 inch Hg and up to 25 )

- nothing happen(it don't release the vacuum (as required)
- no more ''clicking '' of the relay
(with key switch turning on/off)

it look like too much vacuum keep this valve from working

and when the vacuum goes back under (13 inch Hg ) the valve began to work again normaly.

is it a normal condition, because they don't mention anything in the honda service manual about this,
they just say that the valve should'nt hold the vacuum
(no mention about the 13 inch Hg ''possible working condition'' )



can you help me with this problem
thank you