Link2ThePast Posted February 21, 2021 Report Share Posted February 21, 2021 Hi guys, I ran into some trouble with these two outputs on my jumper harness that I made for my mk3 MR2 and can't figure out what is wrong. For the ISC: From what I've gathered, while these valves have 3 pins (12v, ground, auxout), they can be treated like a 2 wire solenoid in PCLink. The stock harness on the MR2 has the plug preconfigured to give it 12v and ground with a single wire for me to operate on the the jumper harness side. Because I think it is operated like a 2 wire solenoid, I have it controlled through AUX 6 on the ExtremeX. I currently have it set its active state to low, but get a fault in the configuration screen unless I put the "test" mode on. I can also remove the fault if I have "test" off and active state set to high side. If I put the "test" on(PWM), I get an error with either low side or high side active state. For the VVT solenoid: I have the same issue as with the ISC. I think the 1zz only has an inlet solenoid, so inlet bank 1 is the one I have configured. I did not touch the exhaust bank 1. Currently it is on AUX 1 and set as low side active state with a fault in the configuration page. I get the same results as above. I have attached the setup pages for both. This is with the car off, I have not started it with the ISC configured. When I had it running (pretty terribly and NA) I still had the fault on the VVT if I remember correctly. Any help/guidance would be greatly appreciated. I'm finishing up outfitting a turbo and I'd like to try and get it running just enough to drive it to a tuner friend who offered to teach me. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 21, 2021 Report Share Posted February 21, 2021 The fault on the ISC may be due to the controller inside the idle valve clamping the voltage. The aux output does an "open load short" test, if it cant float to at least 2/3 batt voltage when "off" then the fault will be generated. We have found some odd controllers clamp the aux voltage to about 7V and will trip this error. If this is the case however, it will still work fine. There are plans to possibly remove that fault check in a future update as we have found a couple of devices that will trip it now. I havent seen any reports from one of these idle valves but it is possibly the issue. Can you hear the valve ticking when you set it to test PWM (temp set the freq to 10Hz so you can hear it better)? If so it will work fine. The VVT solenoid however should not report a fault. That suggests there is an issue somewhere. Does it click in test mode? Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 21, 2021 Author Report Share Posted February 21, 2021 Hi Adam, I'll try it out. No I don't hear any clicking. There is a faint buzzing sound I hear in the bay but I don't think that's what you're talking about and neither solenoid felt like it was moving when I put my hand to them. I'll try putting both tests to on(PWM) at 10Hz to see if I can hear anything. Should I leave them in low side active? Thanks by the way!! Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 21, 2021 Report Share Posted February 21, 2021 At 300Hz they likely wont make any noise as they will just float at some intermediate opening. at 10Hz you should hear tick tick tick... Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 21, 2021 Author Report Share Posted February 21, 2021 Ok so neither one would click when set at 10Hz and test mode set to on(PWM). I'm not sure why either would return the error. My guess for the VVT is that the solenoid is not getting power? Is that why the fault would come on when set to active low side and turns off when set to active high side? Would the same apply to the ISC? There is a PIN that gets eliminated on the jumper adapter I used (yellow wire). Might I need to jump that one with the ecu power? I attached snips of the wiring diagram and circled the relevant lines to make it easier to follow Edit: I added a 4th picture because it shows the line powering the ISC also powering the fuel pump unless I'm reading it wrong Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 21, 2021 Report Share Posted February 21, 2021 With ignition on, and VVT solenoid unplugged, you should have 12V on both of the VVT pins in the VVT solenoid plug. If not then you have the 12V supply missing. For the idle valve you should have see 12V on both pin 1 & 2 in the idle valve plug with it unplugged. Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 21, 2021 Author Report Share Posted February 21, 2021 Would you mind explaining why both pins would be 12v for the VVT, just so I understand? Same for pins 1/2 on the ISC plug? I thought both would pull to ground. Does this mean they should both be set to active high side or am I misunderstanding the help file? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 21, 2021 Report Share Posted February 21, 2021 With the engine not running the ISC and VVT aux outputs will be off. When they are off/not active they are pulled up to 12V. So you should have 12V at the plugs coming from both the main relay, and 12V coming out of the aux output as well. When the ecu needs to open the idle valve or VVT solenoid (i.e when engine is running), then the aux outputs will be connected to ground (low when active). Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 21, 2021 Author Report Share Posted February 21, 2021 Hmm. So currently, the VVT solenoid power is bridged with ECU power, as well as the CAN lambda and I forgot what else. If the CAN lambda is getting power, the solenoid should as well right? As for the ISC, if it turns out I'm not getting 12v from pin 2, then should I do something about the yellow wire that I circled? (meaning power it from the ECU power) Or would both not give me 12V in the event there is no supply? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 21, 2021 Report Share Posted February 21, 2021 If there is no supply you will only have 12V on the aux wire. So do you have 12V on two pins on each device or not? If not, is it the aux wire or the supply wire that doesnt show 12V? Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 21, 2021 Author Report Share Posted February 21, 2021 I'll have to get back to you on this one Adam. I have to get a new multimeter since the last one died and stores are closed in the US right now. For now, assuming it's supply with no 12V, then I have to figure that out on the OEM harness/OEM adapter side. Assuming it's AUX wire, what would be the next step? Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 22, 2021 Author Report Share Posted February 22, 2021 Ok so just an update Adam. I tested the connectors and I only got voltage (around 10V) from the ECU side on each connector. So I bridged my main relay (which is also bridged with ignition switched power on the connector box I made) with the yellow wire and it got rid of the faults. I also tested at 10z and tested the pins. Fixed! I have now another issue where I get back feeding if I leave it like this. I'm only guessing since these are solenoids, the ECU did not turn off after ignition was off and the ECU powered off normally when I snipped the wire jumping them. The faults returned of course. I'm trying to figure out how to prevent this myself on the jumper harness side and not mess with the OEM one. Could you take a look at the wiring diagrams I sent and point me in the right direction when you have the time? I of course am going to still try to do this right now. Thanks for the help! Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 22, 2021 Report Share Posted February 22, 2021 The power supply to any aux solenoid needs to be from an ignition switched source. So you may need to add a relay if you can find a decent existing switched source. Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 22, 2021 Author Report Share Posted February 22, 2021 Right, I understand that. From how I set this up (with the faults), everything is powered through the main relay which is powered by the ignition switch. What I don't understand is why after bridging that yellow wire, which in the original configuration get's supplied constant 12V through the OEM ECM but not until the main relay is triggered through the ignition switch, is now backfeeding(?) the XtremeX If I have it configured only to get power through switched relay power, wouldn't it power down when the ignition switch is off and the key removed? Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 22, 2021 Author Report Share Posted February 22, 2021 ok I have an update. I narrowed the problem down to the VVT solenoid back feeding. The ISC now works. I have it configured as shown in blue. In this state, it is always connected to 12V directly on the (+) side but won't complete the circuit until the ignition is turned on. No fault with the ISC. If I connect the VVT solenoid (+) side to the node shown in blue, I get back feeding and a steady click until ignition is on. I'd like to connect the (+) side to ignition switch power since it is a switched source but it in order for the ISC to work, it also has to be connected to the ignition switch power. The option I had been using before is using the switched battery ( +B ) shown in black, which gets power from the blue node. Before I would not get any power to the solenoid hence the 12V on only one side of the connector. Does anyone see a circuit in the diagram that won't lead to back feeding? Or if I do have it connected as shown, can someone explain why I would have back feeding? Thanks! Quote Link to comment Share on other sites More sharing options...
JMP Posted February 22, 2021 Report Share Posted February 22, 2021 when I make 1zz patch harnesses, I wire the IGSW (B08) pin to the MREL (A21) pin so the main relay is powered on when the ignition is switched on. The ISCV gets its power feed from the stock harness, so you only need to have the RSO (D18) pin connected to your Aux output. For the VVT OCV+ (D24) pin, I patch that into the +B (B16) pin. I never have any backfeeding issues Quote Link to comment Share on other sites More sharing options...
Link2ThePast Posted February 22, 2021 Author Report Share Posted February 22, 2021 Ok so I figured out what my issue was. I had ignition switch supplying the ECU/external sensors, thinking it worked like the switched power portion of the harness, and had the VVT (+) connected to the switched power. Still don't understand why it backfed but I know it doesn't work like that. For anyone who needs it, here's how I have it connected with everything working now: Quote Link to comment Share on other sites More sharing options...
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