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Thread: Controlling dual stage oil pump in 3.6 HFV6 LGZ

  1. #1
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    Controlling dual stage oil pump in 3.6 HFV6 LGZ

    I would like to be able to control the operation of the dual stage oil pump in my supercharged Canyon so that it comes on under certain boost conditions.

    At present the factory programming shuts off the oil pump control solenoid at 4500 rpm which activates the "second stage" high pressure, higher volume.

    While a simple switch or switch and relay could allow this control manually it would be nice to be able to control it through programming.

    Reason for wanting this is the piston squirters only operate at 50-55 psi and above which most of the time is below the first stage oil pressure (typically 37-45 psi hot).

    Second stage oil pressure is typically 80-90 psi using 5W-30 oil.

    Manual control would be OK if not ideal as the time I would want to use it most is climbing a long grade towing at 3500 rpm under boost for example.

  2. #2
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    Interesting idea! Unfortunately, wiring in a manual switch will probably result in random DTCs being set because the ECM performs oil pump control solenoid diagnostics by monitoring the oil pressure versus the commanded state of the solenoid because you're changing the actual state of the solenoid versus what the ECM thinks the state is.

    On some other applications, when we tune them, we set the oil pump to run at full pressure all the time. The main reason they don't run high pressure all the time from the factory is for economy purposes. Obviously, with a supercharger added to the truck, you're more concerned with performance than economy, so I don't see why you couldn't just run at high pressure, all the time. That would help reduce engine component temperatures.

  3. #3
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    It is easy enough to disable the DTC so as not to be annoyed by that, so that is probably the route I will go (manual control) unless someone offers a clever option.

    Would also be OK to just lower the activation rpm to 3500 rpm rather than 4500 rpm, if that was possible. Holley stand alone controller for GDI applications does have a output dedicated to dual stage oil pressure control (the solenoid) which is why I was hoping there was a way to access that through HPTuners.

    Reason not to do it 100% of the time is that there have been cases where at low temperatures the high pressure operation has caused blown oil cooler line fittings on the GM Canyon and Colorado.

  4. #4
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    There is a table that controls that transition point based on oil temperature as well (so you can avoid running high pressure at low temps). If it doesn't exist for this operating systems, maybe ask support if it can be added?

  5. #5
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    Question regarding the simple notion of running a switch on the solenoid control wire. I have that set up, and it works as expected.

    My question is will setting the relevant DTC (which normally report on second error) to no error reported and unchecking the box work to avoid "limp mode" or will the ECU still run the tests anyway and then go to limp mode when oil pressure does not match expected pressure or circuit shows open?

  6. #6
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    GM ECUs have a separate flag that indicates whether the diagnostic itself will run, the DTC settings only control whether the DTC is reported and/or the CEL is illuminated. Remedial actions like "limp mode" will still occur unless you disable the diagnostic itself.

  7. #7
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    Quote Originally Posted by tunerpro View Post
    GM ECUs have a separate flag that indicates whether the diagnostic itself will run, the DTC settings only control whether the DTC is reported and/or the CEL is illuminated. Remedial actions like "limp mode" will still occur unless you disable the diagnostic itself.
    ...and no way to actually disable the diagnostic I assume, so back to square one. When I was testing out the switch and driving with the second stage enabled (i.e. no power to solenoid) I did not get any DTC set, but at least one of the three that are relevant, according to the service manual, could or should cause reduced power mode. Perhaps I just did not have it in that mode long enough, or the DTC immediately reset (except that there is nothing in history).

  8. #8
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    So for what it is worth, so far using the switch on the control circuit to activate the 2nd stage does not set any codes and none stored. I have limited my "experiment" to no more than 5 minutes duration and keeping it between 1500 and 3000 rpm since I know that is well below the ~4500-4100 rpm that the ecu expects to see the 2nd stage operation. For reference with oil warm and oil control solenoid on, the oil pressure runs 35-48 psi, with it off the oil pressure runs 55-87 psi. (That is today with ambient temperature of 98 degF) My understanding is the pressure relief is set to 87 psi so that upper limit makes sense.
    Last edited by c2vette; 05-27-2022 at 04:25 PM.