J.C 10 Posted April 14, 2014 Quick question for all those in search of mpg signal... have any of you got pin 81 connected from the ECU? T121/81 that is. I've been looking and it seems that I don't have a pin in T121/81 but apparently the 1.8t guys are saying that that is the MPG signal. It looks like the MPG signal on the corrado ECU is T68/51 which goes to a 1 pin plug near the fusebox, its a purple/white wire that connects to a white wire that then goes to T28/26. Some people are saying it is tacho related but it would be nice if it is the MPG signal. RESULT!!! T121/81 is in fact an MPG signal, how accurate is yet to be determined but after a VERY leisurly drive to the shops and back my MFA indicates 27.8MPG, like I said I'm not sure how accurate but it is a lot more accurate than 99.9MPG!!!! I'M SO HAPPY NOT TO SEE 99.9MPG ANYMORE:cheers: Quote Share this post Link to post Share on other sites
Sean_Jaymo 0 Posted April 14, 2014 (edited) Winner! Which ECU are you running? ME7 or 7.5? Edited April 14, 2014 by Sean_Jaymo Quote Share this post Link to post Share on other sites
J.C 10 Posted April 14, 2014 I believe it's ME7(ME7.1) Although not sure Winner! Which ECU are you running? ME7 or 7.5? Quote Share this post Link to post Share on other sites
Sean_Jaymo 0 Posted April 14, 2014 I know the 7.5 versions have mpg on pin 81, not sure about the 7.1 versions, they all seem to be tacho on 81? I need to try it out! Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 14, 2014 Ok so I've not uploaded this in the past because most people were getting SWICT or likewise to do their wiring, and it was so long ago I did this and I know for sure i didn't follow it 100%, but anyway I want to take my loom out again soon (getting fast at it now) to put in the MPG wire if it works, good find on that Swiftkid! Also I'd not posted it because I'm not sure the conversion bit is 100% right, but hey it's a starting point and if anything the J220 pinout is really handy (i'm sure that's accurate), took me ages to trace through the diagrams to create it! Anyway, if you spot any mistakes please let me know. Kip VR 24V-12V Pinout.pdf Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 14, 2014 (edited) I'm afraid I'm not 100% sure on the above because I'm working from a MK5/Audi A3 base, this has a fusebox in the engine bay so doesn't have all the coloured plugs. This is what I plan to do, T121 is the main ECU plug which is known as J220 in the wiring diagram, lets call the fusebox in the engine bay fusebox A, this has 2 big plugs going to it - T40 & T26. I'd appreciate if anyone has any comments or can confirm what I've done. F plug 1-Starter wiring, Use corrado wiring 3-Alternator wiring, Corrado G1 1-not used 2-Ambient air temp sensor, use corrado (connects to G2/2) 3-Fuel pump earth trigger, T121/65 4-Ignition live, T121/21 & Ignition coils (T40/33, fusebox A in engine bay) 5-Earth 6 7-ECU relay earth trigger, T121/23 8-fuel pump live (20A fused), Lambda sensors (T26/16 & T26/23 fusebox A) & MAF T26/9 9- 10-ECU relay ignition live, T121/3 11-Speed sender, I don't have this wire but needs putting in, think its T121/54? 12-Tacho signal, for the mk5 apparently I need to put a wire in T121/37 G2 1-Oil temp sender, use corrado 2-Ambient air temp sensor, use corrado (connects to G1/2) 3-Coolant temp sender, use corrado 4-PCV valve T40/26 5-unused 6-unused 7-unused 8-Fuel pump live, T40/37 9-Permanent live, T121/62 ECU - unsure about this as its unfused and needs a fuse, anyone confirm this? 10-Oil pressure switch, use corrado 11-Oil pressure switch, use corrado 12- Z - Injectors T40/21 An additional note, the 109 ecu relay will need changing for a no. 30 relay, unsure exactly why as yet so clarification on this would be good. Now I've got some questions I'm hoping people can answer a few questions please 1. I'm leaving the SAI wiring in, going to put a 330 ohm, 1/2 watt resistor in but there is a power feed to it, where has everyone given power to the SAI from? 2. Is there any difference between fuel pump relays? I was just going to leave the Corrado one in 3. Has everyone used the corrado blue temp sensor and swapped plugs or used the 24v one? It fits in the housing just wondering if it needs swapping 4. T121/66 to rad fan control unit, has everyone just cut this and left the corrado rad fan control unit to do its own thing? 5. N80, Variable valve timing does this go to G1/8? I have written this down somewhere but can't find it. Got a few more bits I need to check but I'll leave that here for now. The rev signal is 37, but in retrospect i wouldn't use it and is the reason i'm taking my loom out again to get the CAN wires back in, the needle jumps about a bit, so better off with a CAN converter I think. I used a fused permanent live from my battery fusebox for the ECU like the Audi 24V does. Edited April 26, 2014 by KipVR Quote Share this post Link to post Share on other sites
swiftkid 1 Posted April 14, 2014 That's awesome news, well chuffed with myself! Just sat I the living room doing some soldering at the moment. Kip what wires do I need for the speed in can bus format? I'm going to see how pin 54 treats me but make it easy to convert back. Never ever want to do this again! Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 14, 2014 You need the canbus twisted pair I think, I'm not sure to be honest as I haven't done it yet!! Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 14, 2014 Also, not all ECU's have a signal output on 54... Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted April 15, 2014 RESULT!!! T121/81 is in fact an MPG signal, how accurate is yet to be determined but after a VERY leisurly drive to the shops and back my MFA indicates 27.8MPG, like I said I'm not sure how accurate but it is a lot more accurate than 99.9MPG!!!! I'M SO HAPPY NOT TO SEE 99.9MPG ANYMORE:cheers: Sounds about right for the 2.8. With the R32 you're better off leaving it at 99.9 :lol: Quote Share this post Link to post Share on other sites
J.C 10 Posted April 15, 2014 Sounds about right for the 2.8. With the R32 you're better off leaving it at 99.9 :lol: Yeah I know, I'm quite impressed with the 25-27mpg (mainly town driving) my old Mk3 golf vr6 and the 2.9 Corrado struggled to out of the low 20's, Could be the low down tourque, not needing to wring it's neck to get power!!! Quote Share this post Link to post Share on other sites
clumpy1 11 Posted April 15, 2014 I was getting better than that in mine Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 15, 2014 Ok so I've not uploaded this in the past because most people were getting SWICT or likewise to do their wiring, and it was so long ago I did this and I know for sure i didn't follow it 100%, but anyway I want to take my loom out again soon (getting fast at it now) to put in the MPG wire if it works, good find on that Swiftkid! Also I'd not posted it because I'm not sure the conversion bit is 100% right, but hey it's a starting point and if anything the J220 pinout is really handy (i'm sure that's accurate), took me ages to trace through the diagrams to create it! Anyway, if you spot any mistakes please let me know. Please note this is using an Audi TT BHE engine Quote Share this post Link to post Share on other sites
VW_OwneR_85 2 Posted April 16, 2014 the rev signal on the BHE is pin 54? , Just to be safe double check this as on my 2.8 BDE and the 1.8T's PIN 54 is VSS input to ecu from fusebox, myself and others have used pin 54 to W-1 with no proplems , leaving this out limited my engine to 4.5k revs.. Good job J.C with the MPG signal looks like ill be opening my harness again to add this :( Quote Share this post Link to post Share on other sites
J.C 10 Posted April 16, 2014 the rev signal on the BHE is pin 54? , Just to be safe double check this as on my 2.8 BDE and the 1.8T's PIN 54 is VSS input to ecu from fusebox, myself and others have used pin 54 to W-1 with no proplems , leaving this out limited my engine to 4.5k revs.. Good job J.C with the MPG signal looks like ill be opening my harness again to add this :( Don't do that just yet, I'm getting an average MPG of 35, I WISH!!! Quote Share this post Link to post Share on other sites
quicky1980 0 Posted April 16, 2014 To those who fitted the late spec fuel filters with integrated pressure regulator. How did you connect to the ports? I've found this part number 6Q0201051A but not sure how to safely connect to the ports as the filter has been designed for quick fit plugs. Great news on the fuel readout, well done! :thumbleft: Will need to try and sort mine out when I get round to tidying the wiring. Quote Share this post Link to post Share on other sites
swiftkid 1 Posted April 16, 2014 Pretty chuffed with myself, been sat many nights staring at wiring diagrams, glad that it's been for some use! Quick, can you not just push the lines on and use fuel clips? I'll need to do this so will be interested on what's needs to be done. Quote Share this post Link to post Share on other sites
Sean_Jaymo 0 Posted April 16, 2014 You should be pleased! These conversions have been happening for 10 years or so and your the first person to apparently spot it :-P I wonder how accurate it is? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted April 17, 2014 Yeah I know, I'm quite impressed with the 25-27mpg (mainly town driving) my old Mk3 golf vr6 and the 2.9 Corrado struggled to out of the low 20's, Could be the low down tourque, not needing to wring it's neck to get power!!! IIRC, the VR6 clocks are calibrated to the injector pulse size of the original 12V injectors. The 24Vs use different injectors (obviously), so the mpg will be reasonably close on the 2.8, but miles off for the R32. We had the same problem with the Supercharger kits back in the day, with the red top injectors. Much smaller injector on-times meant we were seeing 44mpg on the cruise at 70 mph.....yeah right! :D Now I think of it, I think Stealth racing found a fix for that. The 24V is just a more efficient, better designed engine! Much more rewarding to drive at low to medium revs than the 12V. To those who fitted the late spec fuel filters with integrated pressure regulator. How did you connect to the ports? I've found this part number 6Q0201051A but not sure how to safely connect to the ports as the filter has been designed for quick fit plugs. Great news on the fuel readout, well done! :thumbleft: Will need to try and sort mine out when I get round to tidying the wiring. A few options:- 1) Just fudge on some rubber fuel hose (which is what I did). 2) Cut the lines off a salvage R32 / A3 and splice them into your car. 3) Contact United Motorsport for some bundy fittings, but as ever, their website is shyte and they're hard to get hold of. Loads of MK4 & 5 platform cars use the same bundy fittings. Quote Share this post Link to post Share on other sites
swiftkid 1 Posted April 17, 2014 Its a real shame about united motorsport being a nightmare to contact, I had initially wanted to use them for the mapping and other services but having found it impossible to actually contact them in the first place to give them my business I felt if I had any problems I wouldn't have a chance in hell of contacting or getting support. For the MPG on the R32 could you not run an inline resistor to correct the mpg if it is that far out? It doesn't bother me that much about it being highly accurate but if somethings worth doing, its worth doing right! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted April 17, 2014 Yeah it is a shame. I've had dealings with Matt from UM UK and he's a nice bloke, helped me out and is an ace tig welder, but as you say, he's hard to get hold of. I don't think it's as simple as that. The MFA module in the clocks count the number of pulses the from the injector signal, so larger injectors will give you faster pulses causing a wildly optimistic mpg, and smaller injectors will give you larger pulses, and worse mpg! I can't remember what Stealth did. Maybe they tweaked something in the ECU. I'll ask them next time I'm there. Quote Share this post Link to post Share on other sites
J.C 10 Posted April 17, 2014 I don't think it's as simple as that. The MFA module in the clocks count the number of pulses the from the injector signal, so larger injectors will give you faster pulses causing a wildly optimistic mpg, and smaller injectors will give you larger pulses, and worse mpg! I can't remember what Stealth did. Maybe they tweaked something in the ECU. I'll ask them next time I'm there. sounds feasible, I'm averageing 32 MPG since connecting pin 81, that's at least 5mpg more than my petrol pump records show, I wonder whether the 24v injectors supply 20% more flow than the 12v vr6 ones, It's all good, a few more fill ups will give me a correction factor to apply to the readout Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 17, 2014 the rev signal on the BHE is pin 54? , Just to be safe double check this as on my 2.8 BDE and the 1.8T's PIN 54 is VSS input to ecu from fusebox, myself and others have used pin 54 to W-1 with no proplems , leaving this out limited my engine to 4.5k revs.. Good job J.C with the MPG signal looks like ill be opening my harness again to add this :( Balls you're totally right, it's not pin 54 at all. Feeding bad info again...I think it's actually one of the air con signals.. Quote Share this post Link to post Share on other sites
swiftkid 1 Posted April 17, 2014 I believe the rev signal is pin 37? On my engine I don't have it as it's canbus but from what i hear the ecu still sends the signal if I put a pin in there and connect it up Quote Share this post Link to post Share on other sites
KipVR 1 Posted April 17, 2014 I was thinking 37 but didn't want to post it up without being sure this time! I should do as you say and then decide if you can live with the needle jumping a bit. Quote Share this post Link to post Share on other sites