Grant Baker Posted August 2, 2020 Report Share Posted August 2, 2020 Hi Guys! Hope all is well with you? The Honda VTEC solenoid found on the B18C engine (And others) needs 12v to switch. Can this be fired directly from a G4X pin (AUX 6) or does it need a relay? Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 2, 2020 Report Share Posted August 2, 2020 What ecu? Some have high side drives, some don’t. Quote Link to comment Share on other sites More sharing options...
Grant Baker Posted August 3, 2020 Author Report Share Posted August 3, 2020 Fury X Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted August 3, 2020 Report Share Posted August 3, 2020 I have done this in the past with a relay. Best to measure the resistance of the solenoid and calculate the current necessary for operation. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 4, 2020 Report Share Posted August 4, 2020 The highside drives on Aux 5/6/7/8 are rated for 0.5A continuous. Google suggests the B18C vtec solenoid will be between 14-30ohms. So if its 30ohm it will be fine but if its 14ohm it will probably trip out after some time. If yours is more than about 25ohm I would be happy to drive it direct otherwise it will be best to fit a relay. Quote Link to comment Share on other sites More sharing options...
Grant Baker Posted August 4, 2020 Author Report Share Posted August 4, 2020 12.5 Ohm, so will use a relay. Thanks! Quote Link to comment Share on other sites More sharing options...
qiaowei Posted April 20, 2021 Report Share Posted April 20, 2021 Hi Guys! Hope all is well with you? The Honda VTEC solenoid （12.5ohm） and vvt solenoid（7.5 ohm）found on the L15b engine (And others) needs 12v to switch. Can this be fired directly from a G4X pin (AUX 6) or does it need a relay? Hi Guys! Hope all is well with you? The Honda VTEC solenoid （12.5ohm） and vvt solenoid（7.5 ohm）found on the L15b engine (And others) needs 12v to switch. Can this be fired directly from a G4+ force GDI pin (AUX 6) or does it need a relay? Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 20, 2021 Report Share Posted April 20, 2021 Doesnt the L15B Vtec solenoid have two wires? If it has 2 wires then you can just connect one wire to 12V and the other to the ecu aux and use lowside drive. The ECU then only needs to do lowside drive and it can handle 2A. If it only has one wire like the B18C that this post was about then you will need a relay to highside drive it. Quote Link to comment Share on other sites More sharing options...
Electredge Posted June 10, 2021 Report Share Posted June 10, 2021 On 8/4/2020 at 12:11 AM, Adamw said: The highside drives on Aux 5/6/7/8 are rated for 0.5A continuous. Google suggests the B18C vtec solenoid will be between 14-30ohms. So if its 30ohm it will be fine but if its 14ohm it will probably trip out after some time. If yours is more than about 25ohm I would be happy to drive it direct otherwise it will be best to fit a relay. I know this is an old post but its relevant to my question. Link G4x Extreme ECU - can I use Aux 9 or 10 to drive the vtec solenoid via high side? I tested setting it that way in the software... it seems to be possible just wanted to confirm. Ohms tested at 15.5... according to output specs 9 and 10 should do high/low both at roughly 4amps which is more than enough. Thanks Adam, appreciate the help as always Jon Quote Link to comment Share on other sites More sharing options...
aerace_fab Posted June 10, 2021 Report Share Posted June 10, 2021 Curious as to the results of this, from the Documentation it would seem feasible. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 11, 2021 Report Share Posted June 11, 2021 Although the Aux 9/10 hardware would be capable, we dont yet have a high side drive option in the software when they are set to GP Output. I just looked at the documentation for the chipset we use on Aux 5-8 and I reckon one of those will do your Vtec solenoid high side drive no worries. As usual our quoted specs are very conservative. Even though we quote 0.5A, the chipset doesnt over current protect until 6A minimum. However I would only put high load through one of the aux 5-8 channels in this case. Electredge 1 Quote Link to comment Share on other sites More sharing options...
Electredge Posted June 11, 2021 Report Share Posted June 11, 2021 34 minutes ago, Adamw said: Although the Aux 9/10 hardware would be capable, we dont yet have a high side drive option in the software when they are set to GP Output. I just looked at the documentation for the chipset we use on Aux 5-8 and I reckon one of those will do your Vtec solenoid high side drive no worries. As usual our quoted specs are very conservative. Even though we quote 0.5A, the chipset doesnt over current protect until 6A minimum. However I would only put high load through one of the aux 5-8 channels in this case. I assume because the ecu is drawing its high side supply from a single ecu pin? A5... when A5 and B5 are both given 12v does it help at all? or is B5 only for the DBW outputs? Thanks Adam Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 11, 2021 Report Share Posted June 11, 2021 Yeah some of it is related to the single 12v supply pin and probably other considerations such a pcb track widths and heat sinking etc. Pin B5 only supplies the aux9/10 h bridge Electredge 1 Quote Link to comment Share on other sites More sharing options...
Fwdmn Posted February 7, 2022 Report Share Posted February 7, 2022 Dragging this one up from the depths to keep it in one thread, are people fitting flyback diodes for their VTEC and i-VTEC solenoids or is that unnecessary? Quote Link to comment Share on other sites More sharing options...
essb00 Posted February 7, 2022 Report Share Posted February 7, 2022 20 hours ago, Fwdmn said: Dragging this one up from the depths to keep it in one thread, are people fitting flyback diodes for their VTEC and i-VTEC solenoids or is that unnecessary? If using Aux outputs switching high side, no need for fly-wheeling diode. If using Aux outputs switching low side, no need for external fly-wheeling diode (there is one built-in for each Aux output). If using Injection & Ignition outputs used as Aux switching low side, external fly-wheeling diode recommended. Fwdmn 1 Quote Link to comment Share on other sites More sharing options...
Fwdmn Posted February 8, 2022 Report Share Posted February 8, 2022 That is good to know, thank you! Is it still ok to power the ECU, injectors, coils, two solenoids and the three CAS and CAM hall sensors from the Main Relay or is this too much tacked on to one thing? Quote Link to comment Share on other sites More sharing options...
Electredge Posted February 8, 2022 Report Share Posted February 8, 2022 5 hours ago, Fwdmn said: That is good to know, thank you! Is it still ok to power the ECU, injectors, coils, two solenoids and the three CAS and CAM hall sensors from the Main Relay or is this too much tacked on to one thing? depends on the type of coils and injectors but often yes it would be no problem. its all about amperage draw. Quote Link to comment Share on other sites More sharing options...
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