Zealou5 Posted July 6, 2023 Report Share Posted July 6, 2023 Hi guys I wonder if anyone is able to help please? I have an R33 GTST here with a Link G4+ (GTR Link) ECU fitted. I'm having a bit of a problem with the switching of the "ECCS and Coil pack" relays that sit directly behind the ECU from within the ECU. (switched earths from the OEM loom) So originally the car was setup with the above relays running their respective earth triggers straight to the body to earth them out for some reason. The car went for mapping and all was good but ive just come to tidy the wiring and re mount the ECU in the passengers footwell and when I touched the "Coils relay" it felt very warm. (this was with the ignition off and the ecu not powered up). I'm guessing the way it was set up with the permanent earth from the relays this was giving full power to the "coil packs" constantly hence why the relay was hot. I decided to try and re connect the "Coils and ECCS" relays back to the ECU negative switched output to see if this would fix the problem? Well the relay no longer gets hot when wired in like this and the engine ran fine, as id hoped but.... now when i turn the ignition key off the ecu doesn't seem to be breaking it's connection with the earth for the ECCS relay and so all of the dash board warning lights remain on even with the key removed from the ignition. They stay on regardless of if the ECCS relay earth wires to the ECU are connected or not. They only go off when the ECCS relay itself is physically removed from the holder and then when it is then replaced they stay off. So my question is do I need to enable something within the PCLink software to allow the ecu to break the earth connection to those relays when the ignition if turned off/ecu power down? Or do I need to add another output from the "output expansion connector" I fitted to control the external electric fan, (Aux11) to do this earth switching instead? (if so what port and what should it be set to please?) Or do I need to add another relay to break the earth on ignition off? (which seems a bit crazy when the ECU should be able to control this surely?) I hope this all makes a bit of sense, ECU's are not my forte but I'm slowly learning my way around it all. Cheers in advance guys. Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 6, 2023 Author Report Share Posted July 6, 2023 Just had a thought, if i connect the ECCS relay earth to the chassis and not the ecu controlled earth the dash lights go out as they should. With the Coil pack relay connected to the ECU controlled earth the relay no longer gets hot. But weirdly in the OEM wiring harness they share the same earthed output from the ECU (Orange/grey wires) So if I split the shared earth wire to the ecu and ground them as below:- 1. ECCS relay earth to the chassis. 2. Coil pack relay connected to the ECU. would there be any potential issues with doing this? Cheers. Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 6, 2023 Report Share Posted July 6, 2023 So when you say you have "connected the eccs relay back to the ecu negative switched output", is this pin 16? When the relays remain on with the ignition off, what voltage do you have on ECU pin 16 and 45? (back probing with everything still connected). Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 7, 2023 Author Report Share Posted July 7, 2023 Hi Adam, thanks for the reply, Yes the two relays do seem to share that earth at pin 16. (orange and grey wire) But in the pinout diagram it just seems to list it as the ECCS relay not also the coil pack relay earth. Ive attached a few images below showing the two relays which I believe are the coil pack relays and the ECCS relays that sit behind the ECU, (passengers footwell). You can see they share a common earth which looks like its OEM and then it joins behind the blue tape and then terminates at pin 16. Many thanks again, will check the voltages as you suggested too Adam. Cheers Bobby Zealou5 RB25DET_ECR33_Pinout.pdf Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 7, 2023 Author Report Share Posted July 7, 2023 Hi again Adam, So i checked the voltage between pin 16 (as the earth) and pin 45. And there is a small amount of voltage almost negligible maybe? (see attached pic). But its defo only there when the dash lights are on, (see pic) and the relay is in its holder. (this is with the two relays wired up as they should be with the orange negative wire connected to pin 16 on the ECU. Any thoughts would be massively appreciated, Cheers Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 8, 2023 Report Share Posted July 8, 2023 13 hours ago, Zealou5 said: But in the pinout diagram it just seems to list it as the ECCS relay not also the coil pack relay earth. Yeah most RB25's dont even have that ign relay, but RB26's do just like what you have here, so just the diagram doesnt quite match your car, it appears to be wired how I would expect though. 10 hours ago, Zealou5 said: So i checked the voltage between pin 16 (as the earth) and pin 45. And there is a small amount of voltage almost negligible maybe? (see attached pic). What I actually wanted is a voltage measurement on each pin separately. So multimeter black wire to a good chassis ground, multimeter red wire to pin 16, note down voltage, then multimeter red to pin 45, note voltage. And preferably do these measurements when it is not shutting down properly - ie ign switch is off but relays etc are still staying on. Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 8, 2023 Author Report Share Posted July 8, 2023 Hi Adam, thanks again for the replies. Sorry i didn't quite understand the request, but will do that first thing Monday. I did have a bit of a breakthrough last thing Friday afternoon before I left work though. I popped a diode inline with the earths for the 2 relays to the ECU pin 16. (in-case there was some weird feedback looping going on?). I didn't get chance to start the engine as i wanted to check it was safe to do so and ran out of time but it did seem to resolve the problem with the dash lights staying on when the key is pulled out of the ignition. (the lights now go out as they should). I hoping this may be a good fix? I'm just hoping there just won't be any downsides to adding this diode? As if it works as I hope it will that would be great but I don't want it to just be sticking a plaster on a wound that may bring up other issues down the line? Thanks again massively appreciate your help as always buddy. Cheers Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 9, 2023 Report Share Posted July 9, 2023 I cant see how a diode would achieve anything. Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 10, 2023 Author Report Share Posted July 10, 2023 Hi Adam, yeah I'm not totally clear why the diode seems to have resolved the issue of the dash lights staying on but it does seem to have stopped the relay being energised once the ignition is turned off? I wonder if that's why the 2 relays had been grounded to the chassis and not through pin 16 on the ECU when it was first wired in? Is there any way the switched grounding of pin 16 within the ECU could have been setup incorrectly, (through the software at al)l or is malfunctioning? I have also swapped the relays out in case they were latching but this made no difference, (unless the replacement ones too could be coincidentally latching?). But the Diode as a quick fix has done something, hmmmmm, anything else you think i could test apart from those Voltages at pin 16 and pin 45 bud? It's just the time difference between here in the UK and you seems to only give me one shot a day! lols. Cheers again Adam. Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 10, 2023 Report Share Posted July 10, 2023 Pin 16 is not controlled by the ecu, it is a simple FET circuit on the adapter board that just grounds pin 16 when pin 45 has ign signal on it. This is why I want to know the voltages so we can determine which side the issue is coming from. Most likely it is something that has been wired to the ign switch circuit holding pin 45 high. I cant imagine any scenario that the diode will solve. 1 side of the relay coil's should go straight to battery live. The other side to pin 16. For the relay to energise the ecu has to ground pin 16 so current flows from the battery, through the relay coil and back to ground. A diode is basically a "one way valve", so the only way the diode could work was if the current was somehow reversed when you switched off ignition - that would mean the relay coil would have to be disconnected from the battery and connected to ground instead and the ecu would have to be sending voltage out of pin 16 (there is no internal path from pin 16 to battery). The only explanation I can think of would be either the relays arent engaging at all now and instead everything is being powered up by a back feed through something else, or there is something else besides the ecu controlling the pin 16 wire, or those relays have been rewired so the 12+ supply side is not connected straight to battery anymore. Zealou5 1 Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 10, 2023 Author Report Share Posted July 10, 2023 Hi Adam, amazing thanks for this bud. I'll read through this and get the voltages required as soon as I get in this morning. Massively appreciated as always. Cheers again. Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
AbbeyMS Posted July 10, 2023 Report Share Posted July 10, 2023 Bobby, car doesn't have a turbo timer fitted does it? strange as Adam says your can turn the car off with he keys but the relays stay on? With the car off , what voltage do you have at PIN 59? Zealou5 1 Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 10, 2023 Author Report Share Posted July 10, 2023 14 minutes ago, AbbeyMS said: Bobby, car doesn't have a turbo timer fitted does it? strange as Adam says your can turn the car off with he keys but the relays stay on? With the car off , what voltage do you have at PIN 59? Hey Mark, (I assume it's you bud) Cheers for the reply. It does yeah. Ive never ever even tried it to see if it works as its one that looks like it was a almost factory option its integrated so well. Its always just been in the "0" off position (see pic) But i'll definitely check that as another option. And again i'll check the voltage at pin 59. Massively appreciate you chipping in bud, gives me more chances of bites at the cherry! I'll let you know how i get on. Cheers Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 10, 2023 Author Report Share Posted July 10, 2023 Hi guys so here's an update as promised to my findings with regards to voltages at pins 16, 45 and 59 as requested. So with the "ignition off" (no power to ignition and everything wired as it should be i'm getting:- Pin 16 = 8.1Volts Pin 45 = 2.8Volts Pin 59 = 1.8Volts ( no dash lights on). With the key in and the ignition turned "On" and everything wired as it should be i'm getting:- Pin 16 = 0.016 Volts Pin 45 = 12.14 Volts Pin 59 = 12.73 Volts (All with all dash lights on). With the ignition key then taken out and everything wired as it should be i'm getting, (the dash lights staying on event) :- Pin 16 = 8.45 Volts Pin 45 = 4.12 Volts Pin 59 = 4.06 Volts (All as mentioned with all dash staying lights on). If I perform the same test by retrieving the keys from the ignition where the dash lights go out with the diode in place between the relay negative and the ECU pin 16, after resetting the relays i get:- Pin 16 = 8.1 Volts Pin 45 = 3.2 Volts Pin 59 = 2.3 Volts (All with all dash going out, which looking at the voltages is comparable with the first test above "ignition off"). I think AbbeyMS may be onto something as If I turn the dial on the turbo timer with the lights on the engine check light comes on. I'm going to try and disable the Turbo Timer and see if this helps but in the mean time if anyone else has any thoughts on the above values id be very grateful for your continued input. Many thanks again. Cheers Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 10, 2023 Author Report Share Posted July 10, 2023 OK even though there was some funky stuff going on with the turbo timer I'm not sure its the culprit just yet. I disconnected the turbo timer completely from the ignition system, (was actually quite a nice one where the wiring had a 2 connectors from the turbo timer, one that connected to the OEM ignition barrel loom and then another that the original barrel connector went into so quite easy to revert to stock setup, (although getting to it behind the dash in an R33 is a total ball ache!) Looking more into the wiring around the ECU and those two relays for any anomalies i've now noticed that one of the wires from the main loom to the ECCS relay had been cut, (black and white wire) and wrapped up in tape to terminate and then the relay terminal it should go to had been joined/spliced in to the ignition switch live pin 45 wire. So I can only assume the switched live that it should be running wasn't working so maybe it was substituted with a direct feed to the ignition switched live? (pin 45)? This could this potentially be the issue I guess? So..... after a cup of strong coffee..... I took a chance that it was this that was causing my issue as it just seemed like it almost certainly was. (so like in all the good bomb disposal films of the past) I closed my eyes and cut the wire where the relay had been spliced into the power feed of pin 45 and the dash lights instantly went out! I then reconnected the ECCS relay wire back with its original wire from the main loom, (white with black stripe) and the ignition now fires up the dash lights up as it should and all of the lights go out as they should on Key down. Phew! I wont start the car until the morning as the footwell is a mess with all of the dash being taken apart to access the turbo timer but feel like i may have now found the issue. (fingers crossed). Can anyone see a reason this would have been done in the first place please? As If there was a legit reason I don't want to find other issues arise from fixing this one? Thanks everyone for you help/input it's massively appreciated. This as I say really isn't my forte, so having you guys to assist me through things has been really, really helpful. Many thanks all. Cheers Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 10, 2023 Report Share Posted July 10, 2023 2 hours ago, Zealou5 said: So I can only assume the switched live that it should be running wasn't working so maybe it was substituted with a direct feed to the ignition switched live? (pin 45)? It should be permanent live, not switched live. It sounds like they have changed from having the original system of the relay being supplied constant +12V and the ecu switching the ground side, to a permanent ground and the ignition switch switching the 12V side. This may have been something related to the turbo timer or alarm system at some time or it may have had some issue with the ecu switching the ground side and that was the quickest "fix". The trouble with switching from the ignition switch is lots of other devices are connected to that circuit so it is easy to create current paths through other devices. Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 11, 2023 Author Report Share Posted July 11, 2023 Thanks very much for the reply Adam. Im going to see if there are any downsides to going with it wired up correctly and see if the turbo timer is a reason this was done. Many thanks all for the help. I'll let you know how I get on. Is there anything I should be mindful of by reverting to the correct wiring? or if it works should it all be fine? Cheers. Bobby Zealou5 Quote Link to comment Share on other sites More sharing options...
AbbeyMS Posted July 11, 2023 Report Share Posted July 11, 2023 Sounds like the car has had a wire around to enable the ECCS relays from the ignition switch not via the ECU Quote Link to comment Share on other sites More sharing options...
Zealou5 Posted July 12, 2023 Author Report Share Posted July 12, 2023 18 hours ago, AbbeyMS said: Sounds like the car has had a wire around to enable the ECCS relays from the ignition switch not via the ECU Thanks bud, yeah I think you're right! Anyway all seems great! So thanks so much both for helping me through this! Hugely appreciated! Super stars! Cheers Bobby Zealou5 www.zealou5.com Quote Link to comment Share on other sites More sharing options...
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