No VTEC, and no CEL
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1- I can DISCONNECT the pressure switch and get a CEL immeditaly. (It is the 2 pin connector on the side of the solenoid assembly.) I then put it back on and reset the ECU.
2- I can DISCONNECT the solenoid switch and drive up to 8000 rpms on the road, I didn't try further, and NOT get a CEL at all. (This connector has the single yellow/green wire at the top of the solenoid assembly.)
3- I pulled the solenoid assembly off the engine and sent 12v battery power to the solenoid pin (with the yellow green wire normally attached) and properly grounded the assembly (it's normally grounded to the block hence only the power wire going in). The solenoid makes a very slight click sound but the piston in the assembly doesn't move at all. I think that piston is supposed to move isn't it?
This makes me think bad solenoid.
2- I can DISCONNECT the solenoid switch and drive up to 8000 rpms on the road, I didn't try further, and NOT get a CEL at all. (This connector has the single yellow/green wire at the top of the solenoid assembly.)
3- I pulled the solenoid assembly off the engine and sent 12v battery power to the solenoid pin (with the yellow green wire normally attached) and properly grounded the assembly (it's normally grounded to the block hence only the power wire going in). The solenoid makes a very slight click sound but the piston in the assembly doesn't move at all. I think that piston is supposed to move isn't it?
This makes me think bad solenoid.
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From: its back!
Originally Posted by Slows2k,Jun 13 2006, 10:12 PM
Electrically it did work. It didn't have enough oil pressure to keep all the rocker pins locked out.
You also had a low oil pressure warning light flashing at you.
VTEC needs 60+psi of pressure and lots of volume to keep the rocker pins locked out. If one of the rocker pins was missing it would cause a large internal pressure leak and not keep the rockers following the high lift lobe. If the oil pressure falls below the operation threshold 60psi , the oil pressure switch command goes back to "on", and sets the P1259
You also had a low oil pressure warning light flashing at you.
VTEC needs 60+psi of pressure and lots of volume to keep the rocker pins locked out. If one of the rocker pins was missing it would cause a large internal pressure leak and not keep the rockers following the high lift lobe. If the oil pressure falls below the operation threshold 60psi , the oil pressure switch command goes back to "on", and sets the P1259
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From: Mother F'in TN
Originally Posted by hahnn002,Jun 13 2006, 10:01 PM
3- I pulled the solenoid assembly off the engine and sent 12v battery power to the solenoid pin (with the yellow green wire normally attached) and properly grounded the assembly (it's normally grounded to the block hence only the power wire going in). The solenoid makes a very slight click sound but the piston in the assembly doesn't move at all. I think that piston is supposed to move isn't it?
This makes me think bad solenoid.
This makes me think bad solenoid.
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From: Milwaukee Area
Originally Posted by darkfx,Jun 13 2006, 06:17 PM
If the oil pressure isn't within a certain range then VTEC won't work
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From: Milwaukee Area
Originally Posted by hahnn002,Jun 13 2006, 06:22 PM
Exactly, which is one reason I want to check for gunk in the oil filter screen in front of the solenoid. My dipstick show plenty of oil, up at the max line, but I don't have anything to monitor oil pressure yet.
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SOLVED! It was that damn yellow/green (I'll call it YG for short) wire that send 12v to the solenoid. Here's what I did:
I hooked a multimeter up to the single YG wire that goes into the top of the " VTEC Solenoid Valve Assembly" and placed the meter in my lap. Then I went driving to see if 12v was getting to the solenoid when VTEC conditions were met, and I found the 12v was NOT making it to the solenoid.
I then started to run a continuity check on the YG wire from the ECU connector to the single pin solenoid connector (I should have thought of that before), and found the pin at the ECU end was starting to fall out. I reset the pin with some pin tools I have and now everything is good.
Lesson: That 12v signal is NOT monitored by the ECU. Once VTEC conditions are met the ECU sends 12v out to the solenoid but doesn't monitor further to see if the VTEC actually engages or if the solenoid recieves that 12v signal.
Want to test this? Go under your hood, unplug the single YG wire at the top of the solenoid and go for a drive. You will not VTEC, and you will not get a CEL.
Lastly, the Krank Vents had nothing to do with this, them being installed at the same time as the failure was a coincidence only. I also didn't do any recent work on the ECU harness, somehow that pin worked itself out over time. Perhaps starting when I deinstalled a VAFC II last summer it got a little loose and worked out from there.
I hooked a multimeter up to the single YG wire that goes into the top of the " VTEC Solenoid Valve Assembly" and placed the meter in my lap. Then I went driving to see if 12v was getting to the solenoid when VTEC conditions were met, and I found the 12v was NOT making it to the solenoid.
I then started to run a continuity check on the YG wire from the ECU connector to the single pin solenoid connector (I should have thought of that before), and found the pin at the ECU end was starting to fall out. I reset the pin with some pin tools I have and now everything is good.
Lesson: That 12v signal is NOT monitored by the ECU. Once VTEC conditions are met the ECU sends 12v out to the solenoid but doesn't monitor further to see if the VTEC actually engages or if the solenoid recieves that 12v signal.
Want to test this? Go under your hood, unplug the single YG wire at the top of the solenoid and go for a drive. You will not VTEC, and you will not get a CEL.
Lastly, the Krank Vents had nothing to do with this, them being installed at the same time as the failure was a coincidence only. I also didn't do any recent work on the ECU harness, somehow that pin worked itself out over time. Perhaps starting when I deinstalled a VAFC II last summer it got a little loose and worked out from there.
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From: West Coast
Originally Posted by hahnn002,Jun 14 2006, 06:46 PM
I deinstalled a VAFC II last summer it got a little loose and worked out from there.
Good info.
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From: Mother F'in TN
Did you have a PnP harness installed with the VAFCII?
I find this a little odd, as EVERY Honda I've ever worked on with VTEC monitors the VTEC solenoid by the response from the VTEC pressure switch. The solenoid is commanded "on", and the pressure switch goes "off"
Any time you have 2 "on" or "off" signals at the same time for more than a second you get a DTC.
What was the Voltage reading to the solenoid?
I find this a little odd, as EVERY Honda I've ever worked on with VTEC monitors the VTEC solenoid by the response from the VTEC pressure switch. The solenoid is commanded "on", and the pressure switch goes "off"
Any time you have 2 "on" or "off" signals at the same time for more than a second you get a DTC.
What was the Voltage reading to the solenoid?