P51UZ Posted December 3, 2022 Report Share Posted December 3, 2022 When I turn the ignition switch form Run to Off the engine continues to run and the ECU Battery Voltage / Aux9/10 Supply drops from ~14.45V to ~9.8V I measure no voltage from the ignition switch to the Main Relay. I even tried pulling the Main Relay and she keeps on running. I'm having to pull the relay for Ignition & Injection to kill the engine or disconnect the Fuel Pump. I followed the recommended wiring schematics using Aux8 for E-Throttle Relay (Polarity Low, Driver Type Low Side) and Aux4 for Fuel Pump (Polarity Low). The relays seem to work properly when the engine isn't running. Turing the key form Off to Run energizes and latches the Main Relay feeding power to three separate relays (E-throttle, Ignition/Injection, & Fuel Pump) The Fuel Pump relay latches for the expected 3 second prime then unlatches as it should. E-throttle functions properly and when I turn the key from Run to Off all relays unlatch, ECU turns off, and PC Link switches from Online to Searching... Quote Link to comment Share on other sites More sharing options...
aerace_fab Posted December 4, 2022 Report Share Posted December 4, 2022 Something's back feeding/ or the relays are not unlatching. Do you have a schematic you used specifically or a few pictures of how you have the relays wired in? Quote Link to comment Share on other sites More sharing options...
P51UZ Posted December 4, 2022 Author Report Share Posted December 4, 2022 I'll draw it up this evening... Quote Link to comment Share on other sites More sharing options...
P51UZ Posted December 4, 2022 Author Report Share Posted December 4, 2022 @aerace_fab please see attachment... Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 5, 2022 Report Share Posted December 5, 2022 That mostly looks ok. What ecu do you have, and what else is connected to auxes? ah just noticed the topic says xtreme. I suspect it could be the injector drives since that ecu has p&h drives, but still would like to confirm what else is connected to auxes. Quote Link to comment Share on other sites More sharing options...
P51UZ Posted December 5, 2022 Author Report Share Posted December 5, 2022 @Adamw A1 - VVT Sol LH A2 - VVT Sol RH A3 - IACV/ACIS (IntakeAirControlValve/AcousticControlInductionSystem) A4 - Fuel Pump A5 - Engine Fan 1 (Not Wired Up Yet) A6 - OFF A7 - OFF A8 - EThrottle Relay 1 A9 - EThrottle (+) A10 - EThrottle (-) Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 5, 2022 Report Share Posted December 5, 2022 So where does the power for the VVT solenoids and IACV come from? Can you try running it with those 3 solenoids unplugged to see if it turns off with those out of the equation? Quote Link to comment Share on other sites More sharing options...
aerace_fab Posted December 6, 2022 Report Share Posted December 6, 2022 pretty much what adam said. Quote Link to comment Share on other sites More sharing options...
P51UZ Posted December 6, 2022 Author Report Share Posted December 6, 2022 Good idea, I'll try as soon as I get home from work... Quote Link to comment Share on other sites More sharing options...
P51UZ Posted December 7, 2022 Author Report Share Posted December 7, 2022 Ended up working late so it's too quiet to start her tonight but I did check the wiring and it looks like I pulled power for VVT(both banks) & IACV from 30 off my Fuel Pump Relay. Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 8, 2022 Report Share Posted December 8, 2022 A quick explanation video of what I suspect is happening. Back feed.mp4 P51UZ 1 Quote Link to comment Share on other sites More sharing options...
P51UZ Posted December 9, 2022 Author Report Share Posted December 9, 2022 @Adamw Excellent video! Thank you for taking the time to explain this to me. I disconnected the VVT solenoids and IACV and now she shuts off! I'll take your advice and rewire VVT, IACV, & Injectors to 30 on Main... Quote Link to comment Share on other sites More sharing options...
Matt Dunn Posted December 21, 2022 Report Share Posted December 21, 2022 I have struck this problem a few time one some cars I have wired too. What I would do on your diagram to fix it is, Where you have the ign switch only supplying power to terminal 86 on the main relay, and terminal 86 on the other two relays fed from the output of the main relay, I would have the ignition switch switch power to terminal 86 on all 3 relays, and the ouput from the main relay only feeding the +14V on the ECU and connected to nothing else. I have found this way also prevents the issue and depending on the way your loom is made may be an easier option to modify. Quote Link to comment Share on other sites More sharing options...
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