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Oil pressure gauge stuck at 80

Discussion in 'General Chevy & GM Tech Questions' started by BRB46, Feb 3, 2014.

  1. BRB46

    BRB46 Member

    My dash gauge is stuck at 80 with key in run position but engine not running. Also with engine running. Where is the sending unit located for this. 2006 5.3l. Is that the likely problem. About 110K
  2. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member Platinum Contributor 1000 Posts

    The Issue with your Oil Gauge, could be either with the Sending Unit, Wiring Connection or the Stepper Motor for the Oil Gauge has gone out/bad, of the three, I would lean towards the issue being with the Stepper Motor, as its a Common Problem on 2003" to 2006" Trucks/SUV's Dash Clusters.....so much so that GM HAD at One Time, a "Special Coverage Adjustment" on the Dash Cluster for this Issue with the Stepper Motor's.

    The Oil Sending Unit is located at the back of the Engine, on the Driverside, behind the Intake Manifold. It is Best to use a Sending Unit Socket which can be purchased at Most Auto Parts Outlets/Stores.


    Remove the plastic Vortec Intake Cover over the Top of the Engine to gain better access to the Oil Sending Unit.


    View from Rear of Engine

    [​IMG]
  3. BRB46

    BRB46 Member

    Thanks Mike. Whats involved with changing a stepper Motor. Not familiar with that at all. I have seen it mentioned on here before but that's all. I recently had a high voltage problem "15.5v" and have since swapped alternator and that fixed that issue, now less than a week and this pops up. not sure they are related.
  4. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member Platinum Contributor 1000 Posts

    In the Picture, the Stepper Motor's are Circled in Red, there's one Stepper Motor for each Gauge,


    [​IMG]


    The link below is a Write-up with step by step Instructions and with Pictures, on Removing the Stepper Motor's and Installing New Ones, check the link out, and it will give you a clearer picture on Removing and Installing the Stepper Motor's, and where you can buy them etc....

    http://www.gmtruckclub.com/forum/sh...ing-Stepper-Motor(s)?highlight=Stepper Motors
  5. BRB46

    BRB46 Member

    That's great info. Only thing I didn't see was whether or not battery should be disconnected prior to unplugging the cluster. I am not looking forward to that project. Is there anyway to diagnose if the sending unit or stepper is the cause. prior to dis-assembly.
  6. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member Platinum Contributor 1000 Posts

    Your Welcome....you would want Disconnect the Battery when removing the Dash Cluster....on to Diagnose if the Sending Unit or Stepper is the cause.....if you have a Hand-held Scanner, or a Friend has one, that reads Real-Time Engine Data, you would be able to see what the Sending Unit is Registering.

    Last edited: Jun 6, 2014
  7. BRB46

    BRB46 Member

    Thanks, I don't have a scanner or know anyone that does but that's OK. I was looking at them on eBay and might consider one with the LED lamps and change the look. I have good soldering skills so it wouldn't be an issue. Again thanks for the links and your time to help me. Brian
  8. RayVoy

    RayVoy Active Member 1000 Posts

    I'm thinking, what would happen if the cable was disconnected from the sending unit? If the gauge stayed at 80, real good chance the stepper motor is bad. If the gauge falls off, the sending unit might be bad.

    This is not science, just a theory.
  9. BRB46

    BRB46 Member

    The gauge goes to zero with key in off position, otherwise it's at 80. Didn't try to disconnect the sending unit wire. At least not yet.
    Last edited: Feb 4, 2014
  10. RayVoy

    RayVoy Active Member 1000 Posts

    So with power on, it reads max. This could be the stepper motor, with only one "step", max; or, the sending unit produces a voltage change as the pressure changes, maybe the sending unit is only sending max voltage.

    The more I type and think about my previous suggestion, removing the wire will probably remove the voltage just like turning off the key. You probably won't be any farther ahead trying my suggestion.

    You probably need a scope, or a very good DVM to read the voltage changes from the sending unit.

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