Using auxillary output to control exhaust valve

Hello Everyone

Could someone guide me on the feasibility of using Auxillary output on Motec GPR package to activate my varex muffler?

the idea was to link the motec can keypad switch with the auxillary output activation signal, then by pressing the keypad button i would be able to open/close the muffler.

now the issue is that the muffler moves in both directions and requires reversing the polarity, would using a DPDT relay connected to the auxillary output resource do this task?

would appreciate your help as electrical stuff goes right over my head

Hello,

These exhaust valves tend to have their own

controllers but I’d imaging you could get it functioning with the Motec but you’d need to use 2 12v AUX outputs. Is there any motor position or torque sensing feedback for the ECU to know the valve position?

Hey Scott,

i got a timer based controller that would open/close the exhaust valve with the switch. And i tried to connect it to Auxillary output 5 resource so that i could use the available activate switch there. However it seems that the output in this case does not provide the 12V to signal the controller, i think it switches to ground. I have thought then to have it switch a relay and that relay would provide power to the controller but the wiring would get too messy.

Any thoughts?

Normally, you would have an Auxiliary output switch to ground, read the help in M1 tune as to how you setup a switched output. If you need an Aux output to switch to 12V, then you would use a Half-Bridge as the output resource, as these can drive to 12V or ground depending upon the settings.

i tried that, but it seems that the auxiliary outputs are only set to switch to ground in my version of GPR/M1.5 tune.

it does not have the option to select the type of drive.

Read the help for your "Auxilary Outputs x" -- A Duty Cycle of -0 to -100 if used with a Half Bridge will drive the output high (you can still use PWM).

If your version of GPR doesn't do that, then ... how about some clever use of an unused function.

Do you use "Transmission Brake Output"? If not, then perhaps you could use this for your Exhaust Valve.

You can assign a Half-Bridge Output to "Transmission Brake Output Resource', you can define the drive direction. The is controlled by the "Transmission Brake Switch" which can be a Driver Switch (so a CAN message from PDM / Dash or direct switch) or a Keypad Button (if Keypad is controlled by the ECU with no PDM). BTW - set vehicle speed very high to have it stay on with your switch.

Other possibilities, Inlet Manifold Flap or Inlet Manifold Runner -- both have AIM tables with Engine Speed and Manifold Pressure.

Thats great, i'll give them a go and they should probably work. Thanks A lot David!