[4th Gen : 01-07]: Experts! Fuel level/DTE drops quickly. Chased to purge soleniod not working.
Captain
Joined: Sep 2018
Posts: 553
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Just my opinion, but it seems that If this was a programming issue, then it wouldn’t make a difference if the tank was venting properly or not. Up to now the fix has been to remove one of the vacuum lines or pull the filler cap - the BCM (receives fuel level signal) has no way of acknowledging when the EVAP system is active.
I can’t recall if this has been done already and don’t have the focus to go back and read through the thread right now, so sorry if I’m repeating myself.
1) Verify the purge valve isn’t stuck open by checking for vacuum at idle - unhook the line between the canister and purge valve and check vacuum on the purge valve. It shouldn’t be open so there should be no vacuum present. If there is, replace it.
2) Bypass the LDP - unhook the vac line between the LDP and manifold (see diagram in post #12) and cap off the line fitting at the manifold. If the LDP has a leak causing a vacuum draw on the system, then unhooking this line will confirm it.
Expect one or both of these tests to trigger the CEL.
I can’t recall if this has been done already and don’t have the focus to go back and read through the thread right now, so sorry if I’m repeating myself.
1) Verify the purge valve isn’t stuck open by checking for vacuum at idle - unhook the line between the canister and purge valve and check vacuum on the purge valve. It shouldn’t be open so there should be no vacuum present. If there is, replace it.
2) Bypass the LDP - unhook the vac line between the LDP and manifold (see diagram in post #12) and cap off the line fitting at the manifold. If the LDP has a leak causing a vacuum draw on the system, then unhooking this line will confirm it.
Expect one or both of these tests to trigger the CEL.
Thread Starter
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Registered User
Joined: Apr 2020
Posts: 15
Likes: 0
Just my opinion, but it seems that If this was a programming issue, then it wouldn’t make a difference if the tank was venting properly or not. Up to now the fix has been to remove one of the vacuum lines or pull the filler cap - the BCM (receives fuel level signal) has no way of acknowledging when the EVAP system is active.
I can’t recall if this has been done already and don’t have the focus to go back and read through the thread right now, so sorry if I’m repeating myself.
1) Verify the purge valve isn’t stuck open by checking for vacuum at idle - unhook the line between the canister and purge valve and check vacuum on the purge valve. It shouldn’t be open so there should be no vacuum present. If there is, replace it.
2) Bypass the LDP - unhook the vac line between the LDP and manifold (see diagram in post #12) and cap off the line fitting at the manifold. If the LDP has a leak causing a vacuum draw on the system, then unhooking this line will confirm it.
Expect one or both of these tests to trigger the CEL.
I can’t recall if this has been done already and don’t have the focus to go back and read through the thread right now, so sorry if I’m repeating myself.
1) Verify the purge valve isn’t stuck open by checking for vacuum at idle - unhook the line between the canister and purge valve and check vacuum on the purge valve. It shouldn’t be open so there should be no vacuum present. If there is, replace it.
2) Bypass the LDP - unhook the vac line between the LDP and manifold (see diagram in post #12) and cap off the line fitting at the manifold. If the LDP has a leak causing a vacuum draw on the system, then unhooking this line will confirm it.
Expect one or both of these tests to trigger the CEL.
I verified the purge valve opens and closes. I went as far as installing a new unit and it opens and closes the same.
I ordered a new LDP and await for it in the mail.
Thread Starter
|
Registered User
Joined: Apr 2020
Posts: 15
Likes: 0
Just my opinion, but it seems that If this was a programming issue, then it wouldn’t make a difference if the tank was venting properly or not. Up to now the fix has been to remove one of the vacuum lines or pull the filler cap - the BCM (receives fuel level signal) has no way of acknowledging when the EVAP system is active.
I can’t recall if this has been done already and don’t have the focus to go back and read through the thread right now, so sorry if I’m repeating myself.
1) Verify the purge valve isn’t stuck open by checking for vacuum at idle - unhook the line between the canister and purge valve and check vacuum on the purge valve. It shouldn’t be open so there should be no vacuum present. If there is, replace it.
2) Bypass the LDP - unhook the vac line between the LDP and manifold (see diagram in post #12) and cap off the line fitting at the manifold. If the LDP has a leak causing a vacuum draw on the system, then unhooking this line will confirm it.
Expect one or both of these tests to trigger the CEL.
I can’t recall if this has been done already and don’t have the focus to go back and read through the thread right now, so sorry if I’m repeating myself.
1) Verify the purge valve isn’t stuck open by checking for vacuum at idle - unhook the line between the canister and purge valve and check vacuum on the purge valve. It shouldn’t be open so there should be no vacuum present. If there is, replace it.
2) Bypass the LDP - unhook the vac line between the LDP and manifold (see diagram in post #12) and cap off the line fitting at the manifold. If the LDP has a leak causing a vacuum draw on the system, then unhooking this line will confirm it.
Expect one or both of these tests to trigger the CEL.
Im ready to get done with this once and for all.
Registered User
Joined: Apr 2025
Posts: 1
Likes: 0
I tried messaging you, but because I'm new it won't let me. I can't wait forever to find out if you figured it out.