Evap Bypass Not Opening WHY???
01-15-2013, 04:31 AM
#1
Honda-Tech Member
Thread Starter
Join Date: Jan 2013
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Evap Bypass Not Opening WHY???
I have a P1456 code. I do not have any vacuum leaks (internal or external). CNS, PURGE, BYPASS, all work by grounding wires on the ECM.
When driving, the FTP is not showing any sudden changes to indicate that vacuum is being pulled on the tank. However, with the CNS valve closed and the BYPASS valve open, the PURGE DOES PULL VACUUM ON THE SYSTEM.
So, the purge is opening, but the bypass is not (unless I make it). What would cause this? Is a bad ECM the only possibility?
When driving, the FTP is not showing any sudden changes to indicate that vacuum is being pulled on the tank. However, with the CNS valve closed and the BYPASS valve open, the PURGE DOES PULL VACUUM ON THE SYSTEM.
So, the purge is opening, but the bypass is not (unless I make it). What would cause this? Is a bad ECM the only possibility?
Thread
Thread Starter
Forum
Replies
Last Post
RoscoeT
Honda Accord (1990 - 2002)
2
07-25-2015 09:12 PM
