Results 1 to 4 of 4

Thread: AEM Wideband Voltage Drop On HPT Pro

  1. #1
    Tuner in Training
    Join Date
    Mar 2008
    Posts
    15

    AEM Wideband Voltage Drop On HPT Pro

    Sorry for the long post. My HP Tuners connection appears to be messing up my wideband outputs.

    I have 2 AEM inline wideband controllers (30-0310).
    Hooked into HP Tuners Pro.
    Brown Wire On Pin 5 and White Wire On Pin 1 for Left bank and Pin 6 and 2 For Right Bank.
    Pin 5 and 6 also grounded to the body

    Aeroforce Interceptor Scan Gauge single wires ALSO hooked into pins 1 and 2 so the widebands will show up on the Interceptor.

    I had planned on using either HPT or Aeroforce but not both at the same time. They both power on via OBD port, so only would plug one in as needed.

    The Aeroforce displays 14.1 or 14.0 for both widebands if they are connected to HP Tuners... but no higher. The widebands voltage output actually drops to 2.95 or so, car off. If you connect HPT to a laptop (still no OBD plugged in) the AFR display goes back to normal. 17.8 with car off... almost 5 volts i think. If you unplug the green connector, it reads normal also.

    I double checked resistance to ground and the power supply. Everything looked ok. Why would an unpowered, yet connected HP Tuners lower the voltage output of my widebands? Is there a better way to connect everything?
    It appears to be logging right in HPT for AFR. My lambda setting must not have been right, but I think thats just a setting that needs adjusted.

    I'm sure I'm doing something wrong. I've never had problems in the past with AEM, but just didn't want more than 1 gauge for 2 widebands. Car is a 2012 CTS-V Wagon if it matters.
    Thanks

    Edit - I found a couple threads with similar issues, but no answers.
    https://forum.hptuners.com/showthrea...-not-hooked-up
    https://forum.hptuners.com/showthrea...HPtuners-cable
    Last edited by Batwood; 07-28-2018 at 02:24 PM.

  2. #2
    Advanced Tuner
    Join Date
    Dec 2005
    Location
    Posts
    599
    There MAY be a protection diode in the MPVI that goes from the input to the internal +5v supply rail. But, that rail is at 0v , if the unit is not powered up. So, it may drag the output down. Just a possibility?

  3. #3
    Tuner in Training
    Join Date
    Mar 2008
    Posts
    15
    I guess I decided to just unhook the green plug on HPT when I'm not using it.

    New problem: One AEM controller reads considerably leaner than the other. I even swapped them from left to right banks and it stays 1.5-2 AFR points leaner. Same reading when warming up and same reading when the car isn't running.
    I've never had this many problems with widebands. Just had to return an Innovate dual setup after 3 weeks due to a bad gauge.

  4. #4
    Advanced Tuner
    Join Date
    Dec 2005
    Location
    Posts
    599
    Does the lean condition follow the sensor or the controller ?

    Does doing a free-air-cal on both controllers help ?

    And... where are the 30-0310s getting a ground reference from, with the green terminal block disconnected ? They both need ground for the DAC- ( or whatever they call it ) wire.