Ykuri5343 Posted September 26, 2023 Report Share Posted September 26, 2023 Hello first timer here. I’ve been reading the different ways everyone on here has been doing to make the ecu connect but I have no luck, let alone no light turns on the ECU when ignition is on. I have installed many of the drivers but still nothing. I have a wiring specialties harness that is plugged with the ARC switch panel. Can someone please help me Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 26, 2023 Report Share Posted September 26, 2023 What ecu do you have? A wire-in or an HC20X plug-in? Quote Link to comment Share on other sites More sharing options...
Ykuri5343 Posted September 26, 2023 Author Report Share Posted September 26, 2023 1 hour ago, Adamw said: What ecu do you have? A wire-in or an HC20X plug-in? I have the HC20x plug-in Quote Link to comment Share on other sites More sharing options...
Ykuri5343 Posted September 27, 2023 Author Report Share Posted September 27, 2023 On 9/26/2023 at 5:29 AM, Adamw said: What ecu do you have? A wire-in or an HC20X plug-in? I have the HC20x plug-in I should have a little time after work to go through the harness and see if they are all in the right slots for the ECU pin out. I have seen some threads where you might have to jump the ecu. Would I possibly have to do the same? Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 27, 2023 Report Share Posted September 27, 2023 It should work out of the box with no changes to configuration or wiring. To help troubleshoot your wiring, the power supply circuit works like this: The ignition switch signal is pin E9, you should have +12V on this pin when the ignition switch is in ON and Start positions. When pin E9 has =12V, the ECU will connect pin E7 to ground, this pin controls the main EFI relay. You should see 12V on this pin when the ignition is off and ground when the ignition is on. When E7 is grounded the main efi relay will engage and supply the main 12V to pins A2 and A3. Confirm you have 12V on these pins when E7 is grounded. Of course, you need grounds as well - so check A4 & A5 have good continuity to ground. Quote Link to comment Share on other sites More sharing options...
Ykuri5343 Posted September 28, 2023 Author Report Share Posted September 28, 2023 I have 12v off of a7 and a9 but nothing off of e7 and e9 It also seems like I don’t have any wire in a3 Quote Link to comment Share on other sites More sharing options...
aerace_fab Posted September 28, 2023 Report Share Posted September 28, 2023 wiring specialties harnesses are known to not be pinned right, you might want to go over that whole harness. Quote Link to comment Share on other sites More sharing options...
Ykuri5343 Posted September 28, 2023 Author Report Share Posted September 28, 2023 1 hour ago, aerace_fab said: wiring specialties harnesses are known to not be pinned right, you might want to go over that whole harness. That’s really annoying I guess I’ll call them in the morning and see what they say. For some reason, it seems like it’s missing lots of wires if I were to go off the wiring diagram Would the knock sensor usually have 12v when ignition is on? Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 28, 2023 Report Share Posted September 28, 2023 Looking at your pic, that looks like possibly they have the E plug wires inserted into the A plug housing? The plugs are very similar 31P housings, just a different keyway on the bottom, so possibly easy to mix up. Your A plug looks like it has no wires in the middle row A10-A21, but many of these are essential pins so I dont think they would normally be left out on purpose. A10 & 11 are the main sensor grounds, A15 is TPS, A18 is speed, A20 & 21 is the 5V supply... Hopefully it hasn't fried anything. Quote Link to comment Share on other sites More sharing options...
aerace_fab Posted September 29, 2023 Report Share Posted September 29, 2023 18 hours ago, Ykuri5343 said: That’s really annoying I guess I’ll call them in the morning and see what they say. For some reason, it seems like it’s missing lots of wires if I were to go off the wiring diagram Would the knock sensor usually have 12v when ignition is on? 12v should not be present at the knock sensor. Quote Link to comment Share on other sites More sharing options...
Ykuri5343 Posted September 29, 2023 Author Report Share Posted September 29, 2023 Alright so I figured it out. The way it was loomed, I had put the A and E plug in the opposite ports. I don’t know why I never thought of switching them to see if it will work… I feel like a dummy haha Thank you for the help! Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 30, 2023 Report Share Posted September 30, 2023 They shouldnt even fit. Quote Link to comment Share on other sites More sharing options...
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