Mot Posted February 20, 2019 Report Share Posted February 20, 2019 Hey everyone! I'm trying to switch a relay for a magnetic valve that controls an exhaust valve, but seem to be running into a problem. Using Aux 7 and this type of relay. Managed to set it up as GP Out / high drive, because the solenoid needs the 12v to switch. If I use the test (on) on the GP Out, I get the expected output of 12V. However if I connect this to the relay, the voltage drops to zero. Tried connecting it directly to the solenoid, but the same thing happens. Probably because the load without a relay would be too high. What am I doing wrong here? Is there a general downside to using an aux port as high side driven? Can post a wiring diagram/pictures tomorrow, but it's 3 am here already and I'm done for today :-( Thanks & regards, Thomas Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 20, 2019 Report Share Posted February 20, 2019 Most of the Plug-in ECU's (GTT included) donot have highside drives, they can only do lowside - even tho the highside setting is available in the software. Quote Link to comment Share on other sites More sharing options...
Mot Posted February 20, 2019 Author Report Share Posted February 20, 2019 Huh? Meaning that it will show an output of 12V on the Aux 7, but if connect a load to it, the voltage will drop/it won't work? Wouldn't it be better if it didn't output anything at all then? Regardless of what the software says. Guess I'll have to put another relay in, that I can lowside drive to output my desired 12V then? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 20, 2019 Report Share Posted February 20, 2019 1 hour ago, Mot said: Meaning that it will show an output of 12V on the Aux 7, but if connect a load to it, the voltage will drop/it won't work? It has a weak 12V pull-up so it will go to 12V when it is off but it wont have enough current to drive a relay. This is done so that things like a tacho that needs a 0-12V pulse will work. 1 hour ago, Mot said: Guess I'll have to put another relay in, that I can lowside drive to output my desired 12V then? Why dont you just put 12V to the other side of the relay coil like the help file shows? Like this: Quote Link to comment Share on other sites More sharing options...
Mot Posted February 20, 2019 Author Report Share Posted February 20, 2019 3 hours ago, Adamw said: It has a weak 12V pull-up so it will go to 12V when it is off but it wont have enough current to drive a relay. This is done so that things like a tacho that needs a 0-12V pulse will work. Shouldn't this be in the known issues section of the manual then? Would have a saved me a lot of time and head ache. 3 hours ago, Adamw said: Why dont you just put 12V to the other side of the relay coil like the help file shows? Like this: Yeah, I'll do that then. I will however need a second relay to do it. The existing one needs to be high side driven, because there was an existing remote control (key fob) for the exhaust valve already in the car, which I wanted to keep. So wiring the Link aux in parallel with a blocking diode seemed the easier way to do it. Quote Link to comment Share on other sites More sharing options...
Canisbellum Posted February 20, 2019 Report Share Posted February 20, 2019 (Shouldn't this be in the known issues section of the manual then? Would have a saved me a lot of time and head ache) Its not an issue its how 12v systems work. Quote Link to comment Share on other sites More sharing options...
cj Posted February 20, 2019 Report Share Posted February 20, 2019 1 hour ago, Mot said: The existing one needs to be high side driven, because there was an existing remote control (key fob) for the exhaust valve already in the car, which I wanted to keep. I dont know which product exactly you have but arent these the things you hold down the button for ~5 seconds to open it, and a different button to close it? This may not be just a simple case of "turn on a relay and leave it". You potentially have to have a timer (which the ecu can do) so it only triggers the output for ~5 seconds so it doesnt burn out the motor driving it "more open" the entire time. If you havent done it already, it would pay to stick a multimeter on whichever side of the controller box this thing presumably has where you plan to splice into the wires and confirm that a) its electrically just an on/off switch, and not a "swap the voltage over to drive the motor shut" arrangement b) figure out whether it drives the motor permanently, just for a second, or for a set amount of time. (and the same for closing it) The last one of these I saw was basically just a DC motor attached to a throttle butterfly and you had to provide reverse current to close it, which is do-able using 2x outlets and some careful arrangements of relays but it requires a bit of planning Quote Link to comment Share on other sites More sharing options...
Mot Posted February 20, 2019 Author Report Share Posted February 20, 2019 5 hours ago, Canisbellum said: (Shouldn't this be in the known issues section of the manual then? Would have a saved me a lot of time and head ache) Its not an issue its how 12v systems work. Excuse me? - having the option to enable it in the software - the ECU measurably doing it - then failing without further notice - the manufacturer stating some of the ECU's don't support this, but it's not mentioned exactly which ones - no indication in the manual either I don't think "that's how 12v systems work" is the right description of the problem here. 5 hours ago, cj said: I dont know which product exactly you have but arent these the things you hold down the button for ~5 seconds to open it, and a different button to close it? This may not be just a simple case of "turn on a relay and leave it". You potentially have to have a timer (which the ecu can do) so it only triggers the output for ~5 seconds so it doesnt burn out the motor driving it "more open" the entire time. If you havent done it already, it would pay to stick a multimeter on whichever side of the controller box this thing presumably has where you plan to splice into the wires and confirm that a) its electrically just an on/off switch, and not a "swap the voltage over to drive the motor shut" arrangement b) figure out whether it drives the motor permanently, just for a second, or for a set amount of time. (and the same for closing it) The last one of these I saw was basically just a DC motor attached to a throttle butterfly and you had to provide reverse current to close it, which is do-able using 2x outlets and some careful arrangements of relays but it requires a bit of planning The remote control tells a little black box to permanently send 12v to the magnetic valve, which in turn opens to let the vacuum through to the exhaust flap. If you remove the 12v from the solenoid, the valve will shut and the flap will open. Quote Link to comment Share on other sites More sharing options...
Richard Hill Posted February 20, 2019 Report Share Posted February 20, 2019 9 hours ago, Mot said: Excuse me? - having the option to enable it in the software - the ECU measurably doing it - then failing without further notice - the manufacturer stating some of the ECU's don't support this, but it's not mentioned exactly which ones - no indication in the manual either I don't think "that's how 12v systems work" is the right description of the problem here. The remote control tells a little black box to permanently send 12v to the magnetic valve, which in turn opens to let the vacuum through to the exhaust flap. If you remove the 12v from the solenoid, the valve will shut and the flap will open. The ECU is not "measurably doing it" (high side driving) , it has a weak pull-up on the AUX outs. A multimeter won't load the output enough to show that it can't supply the current required for a relay. I do agree though that there should be more concise documentation as to which ECUs can support high side driving as the help file released with 5.6.6.3601 a couple of days ago says :- "G4+ Auxiliary Output Specifications: · 1.5k Ohm Internal Pull-up Resister · Auxiliary Drive Low 2A over-current protected · Open Collector (fly-wheeled) in auxiliary output mode. · Aux 5 to 8 High Side Drive (ISC Stepper Mode) 0.5 A. · Aux 9 and 10 (only on: Xtreme, Fury, Thunder, Force GDI and selected Plugin ECUs) Push-Pull drive 4/4 A" I think this is ambiguous as the above bracketed (ISC Stepper Mode) isn't really a fully qualified statement. The monsoon for example has aux 5 and 6 but can't high side drive. Quote Link to comment Share on other sites More sharing options...
Simon Posted February 20, 2019 Report Share Posted February 20, 2019 On the wire in units that have AUX5-8 it would high side drive on those outputs fine. On a plugin the board it has been designed to be lowside driving on all 4 outputs as this is what is required for the factory functions on those pins. The main PCB actually doesn't have the hardware to allow highside driving. On cases such as the Honda plugin additional hardware is added to the sub-board to allow the high side driving of the VTEC solenoid. The Known issues section is for where there is a issue on a stock / factory application. Quote Link to comment Share on other sites More sharing options...
Mot Posted February 21, 2019 Author Report Share Posted February 21, 2019 On 2/20/2019 at 4:45 AM, Adamw said: Why dont you just put 12V to the other side of the relay coil like the help file shows? Like this: FYI: Did this today and it worked. Also measured how large the load from the realy was - a whopping 0,18A... I do understand that the plug-in boards are designed to provide all the necessary functions for stock/OEM cars. I do not understand the lack of documentation concerning the matter. Glad for the support in the forums though! So keep up the good work here! Quote Link to comment Share on other sites More sharing options...
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