Vtec Oil Pressure Block off
09-18-2012, 09:26 AM
#55
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I'm not 100% sure but everyone saying that it is only pressurized when VTEC is engaged I think might be wrong. I believe this sensor detect if enough oil pressure is available BEFORE engaging VTEC, therefore pressure is always at this port even if VTEC is not engaged. VTEC requires a lot of oil, if for some reason your oil pressure is low, you wouldn't want it to drop even lower when VTEC engages. Engine management systems can disable this circuit requirement of course like everyone else has already stated.
09-18-2012, 01:25 PM
#57
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I can't say what the scan tool says I haven't looked but I think the switch has constant oil pressure. I can't see how an EMS could require this if it doesn't respond until after the solenoid is activated.
09-18-2012, 01:31 PM
#58
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So quit speaking on what you don't know...
The ecu uses the VTEC pressure switch to know when. To switch over to the high cam maps and uses it to make sure the VTEC system is working. If the ecu commands the solenoid to turn on but does not see the pressure switch change state then it knows there is a problem and throws a cel.
There is not constant oil pressure at the switch. There is only pressure after the VTEC solenoid has been activated.
The ecu uses the VTEC pressure switch to know when. To switch over to the high cam maps and uses it to make sure the VTEC system is working. If the ecu commands the solenoid to turn on but does not see the pressure switch change state then it knows there is a problem and throws a cel.
There is not constant oil pressure at the switch. There is only pressure after the VTEC solenoid has been activated.
09-18-2012, 01:54 PM
#59
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if the oil light on the dash is on, then the wire going to the oil pressure sender is grounded out somewhere.
again this is different than the oil pressure switch for VTEC.
This is what the sender going to the oil light on the dash looks like. This is located next to the oil filter with a single wire going straight to the oil light on the dash. When oil pressure is low, this sender applies a ground to the wire and turns the light on the dash on.
The oil pressure switch in this picture is the one that tells the ecu when the vtec system is pressureized. this is what the block off plug in this thread gets rid of. This has absolutely nothing to do with the oil light on the dash as there is only pressure here AFTER vtec is turned on. This has 2 wires going to it. A sensor ground and a signal wire going back to the ecu. When vtec is not engaged, this switch is off, when vtec comes on and the system is pressureized, the switch turns on and sends a ground signal to the ecu. This way the ecu knows that vtec has turned on properly. You can monitor this in aem pro/tuner by monitoring the switched input that corresponds to this input.
again this is different than the oil pressure switch for VTEC.
This is what the sender going to the oil light on the dash looks like. This is located next to the oil filter with a single wire going straight to the oil light on the dash. When oil pressure is low, this sender applies a ground to the wire and turns the light on the dash on.
The oil pressure switch in this picture is the one that tells the ecu when the vtec system is pressureized. this is what the block off plug in this thread gets rid of. This has absolutely nothing to do with the oil light on the dash as there is only pressure here AFTER vtec is turned on. This has 2 wires going to it. A sensor ground and a signal wire going back to the ecu. When vtec is not engaged, this switch is off, when vtec comes on and the system is pressureized, the switch turns on and sends a ground signal to the ecu. This way the ecu knows that vtec has turned on properly. You can monitor this in aem pro/tuner by monitoring the switched input that corresponds to this input.
Helms:
As measured at VTEC switch port:
VTEC not engaged: below 7 psi oil pressure
VTEC engaged: above 53 psi oil pressure