loonysalmon Posted August 22, 2009 Share Posted August 22, 2009 Hi there! I posted a question a bit ago in regards to getting an ECU for my subbie and have since received it and installed it. To my surprise, the new ECU didn't fix my problem and I now am tracing what the problem is at this point. So far I have re-ran the ECU wiring harness and installed a new ECU to ensure that I have a clean start on the wiring. Since we can rule the wires going to the ECU out, what does this ECU require to at least turn on, in terms of power and other things. I need to get this car running before I start school--leaving on Thursday early morning for MTU. Any help from this community would be thoroughly appreciated as I love my Subbie. Thanks a lot in advance, -Tom Link to comment Share on other sites More sharing options...
Cougar Posted August 22, 2009 Share Posted August 22, 2009 Just off the top of my head I think power is usually provided to the ECU through the main relay. What are the problems you are having? I assume you are not getting spark to the plugs, is that so? If it is you need to check for power getting to the ignition system. Link to comment Share on other sites More sharing options...
loonysalmon Posted August 22, 2009 Author Share Posted August 22, 2009 Cougar, I am not getting power to the Ignition coil or the Fuel Pump, which leads me to believe that it is the ECU that is not sending power to the relays that control the power for these parts. I've got the FSMs here so I'll start paging through them to see what I can't find. I traced it before and it came back to the ECU controlling power to these relays. Without the ECU getting power, I am without a check engine light and even with the green diagnostic connectors joined together, I have no led flashes from the ECU. Something is amiss here. -Tom Link to comment Share on other sites More sharing options...
Cougar Posted August 22, 2009 Share Posted August 22, 2009 Have you checked all the fusible links and fuses? Link to comment Share on other sites More sharing options...
loonysalmon Posted August 22, 2009 Author Share Posted August 22, 2009 Have you checked all the fusible links and fuses? How would I go about checking the Fusible Links? Ammeter before and after and ensure continuity?? Link to comment Share on other sites More sharing options...
Cougar Posted August 22, 2009 Share Posted August 22, 2009 You can usually just feel them and tell if they are good or not or bend the middle of them where they burn out at. You can also check the voltage across them while in the circuit. A good one will have no voltage across it since it is basically a short circuit. You need to have voltage going to one end at least of course. Another method is to remove it and measure the resistance across the link. It should be zero ohms. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted August 22, 2009 Share Posted August 22, 2009 Find out where you are losing power. It's a pretty simple matter to look at the MPFI wireing diagram and trace all the power leads and which pins they connect to. You have an ignition relay that provides main power to the ECU when the key is turned on - I would start there. GD Link to comment Share on other sites More sharing options...
Cougar Posted August 22, 2009 Share Posted August 22, 2009 I got out my service data. You didn't state if you have the 4 or 6 cylinder version but either way, if you have no voltage at the coil check fuse 11. If you have no voltage at fuse 11 then you should check the fusible links. My data shows fuse 11 is fed power from the taillight relay which makes absolutely no sense to me and I can't find it on any drawing. Check your data to see how fuse 11 is supplied power. It may show something different. Link to comment Share on other sites More sharing options...
loonysalmon Posted August 22, 2009 Author Share Posted August 22, 2009 You didn't state if you have the 4 or 6 cylinder version I have the four cylinder version. I'm still working on getting a multimeter at this point. I thought I had one of mine, but both are back at home! Link to comment Share on other sites More sharing options...
loonysalmon Posted August 22, 2009 Author Share Posted August 22, 2009 Hey again. So I checked the fusible links themselves with a setting of 200 on the multimeter and the links were coming up with 20-30 for the resistances. I also got a hold of a battery charger so I can have a battery to work with when I want to do work on this car, instead of jumping it up every time. I'm sure I'll have more details for you all tomorrow, however until now, I'm calling it for the night. Thanks so far, and I expect to continue on this ordeal until it is finished--or at least until Thursday morning. -Tom Link to comment Share on other sites More sharing options...
Cougar Posted August 22, 2009 Share Posted August 22, 2009 If you have a test light probe that will also work to check for voltage. Link to comment Share on other sites More sharing options...
john in KY Posted August 23, 2009 Share Posted August 23, 2009 Fuse #11 goes hot when the key is either in the RUN or START position. This circuit includes the fuel pump relay and the ign coil. If the fuse is good maybe the problem is in the Ign SW. Go in the trunk and unplug the ECU. Find the single red wire and test for flow. It is suppose to be always hot. PM your email address. I have an ECU pinout diagram in PDF format that I can't for reasons unknown to me cut and paste. (Mac OSX) Thinking I can send it via email. John Link to comment Share on other sites More sharing options...
loonysalmon Posted August 23, 2009 Author Share Posted August 23, 2009 Which fuse would happen to be #11? How does the counting work? And yes, the red wire has power. Also, I checked all of the fuses visibly and they all looked fine. Maybe it's in the iggy! And yes, I have the multimeter now. Lets have this problem checking begin tomorrow morning! I can almost see the white light at the end of the tunnel!!! Link to comment Share on other sites More sharing options...
Cougar Posted August 23, 2009 Share Posted August 23, 2009 I'm not sure if the fuse panel is laid out like my drawing shows but it may be. It shows 2 columns of 8 fuses and third column with 4. Number 1 fuse is the top of of the first column of 8 fuses. Fuse 17 is start of the third column. So fuses 1, 9, and 17 are at the top of the column. Fuses 10 and 12 also tied to the power side of fuse 11 so if it doesn't have power getting to it then neither will they. Link to comment Share on other sites More sharing options...
Gloyale Posted August 23, 2009 Share Posted August 23, 2009 Does your Check engine light illuminate when you turn the key to *on*? If yes, then move next to the ECU itself. Is it blinking any codes at you? any lights at all on it? If both of these are yes, then the ECU does have power, it jsut isn't passing it through to the IG. and FP. Test the fuel pump relay by connecting the green test connectors and turnong the key to *on* Fuel pump Cycle?(otherwise, fuel pump only runs when an ignition pulse is detected. Link to comment Share on other sites More sharing options...
loonysalmon Posted August 23, 2009 Author Share Posted August 23, 2009 Does your Check engine light illuminate when you turn the key to *on*? NO Test the fuel pump relay by connecting the green test connectors and turnong the key to *on* Fuel pump Cycle?(otherwise, fuel pump only runs when an ignition pulse is detected. not sure, will check this out in a bit here. Link to comment Share on other sites More sharing options...
Gloyale Posted August 23, 2009 Share Posted August 23, 2009 NO Fuse 12 supplies power to the light and meters. But if it isn't lighting then you are right, you have no power to the ECU. Check that Pins 10, 20, 30(AT only) 56,57,60,and 61 of the ECU all are grounded. (Black and Black/red wires) If no then check the gound bolt on the engine where the harness is attached. That is where all the ECU grounds source from. Link to comment Share on other sites More sharing options...
Gloyale Posted August 23, 2009 Share Posted August 23, 2009 Cougar, I am not getting power to the Ignition coil or the Fuel Pump, which leads me to believe that it is the ECU that is not sending power to the relays that control the power for these parts. OK re-read some of the earlier posts in the thread. ECU does not power the Ignition coil. Ignition coil is powered by Black/white wire originating from Fuse 11. the wire splits, and supplies power also to the Ignition relay, which then turns on the ECU. But if you have no voltage to the coil. there is CERTAINLY a problem in that BW wire. Same wire goes to these locations: From fuse 11, Splits to supply FP relay, then splits to diode that supplies IG/ECU. relay Through connector R2(green 21 pins) then splits to supply Purge solenoid Splits again to supply IG.coil, and to test connector T11 and finally supplies power to ECU pin 19. SO.......disconnect the following: Ig. relay FP relay Purge solenoid (or just disconnect whole engine harness) Unhook BW wire from ignition coil. Disconnect ECU. NOW..... using long test leads, check for coninuity (200 Ohm setting) from each end to end of that BW wire. Use this method to track down which portions of this wire are not continuous. Alternately, you could just test for 12v down the line on this wire. Link to comment Share on other sites More sharing options...
john in KY Posted August 23, 2009 Share Posted August 23, 2009 If he hot wires the positive side of the coil this will backfeed the fuel pump relay. The fuel pump will run and the coil will be hot. Engine just may start. Offered to email you an ECU pinout diagram but appears you don't want it. Link to comment Share on other sites More sharing options...
Gloyale Posted August 23, 2009 Share Posted August 23, 2009 If he hot wires the positive side of the coil this will backfeed the fuel pump relay. The fuel pump will run and the coil will be hot. Engine just may start. Correct, that would backfeed the FP relay. That would supply it with power, however without a functional ECU to ground the signal pin of the relay it the Fuel pump will not run. And Besides, if there is a break in the wire somewhere, power will still not get everywhere it needs to. I wouldn't try that method. At best that is a troubleshooting idea. But it isn't the best one. Multimeters and Wiring diagrahms exist for a reason. If he follows my instruction in my last post he WILL find the problem. Link to comment Share on other sites More sharing options...
loonysalmon Posted August 23, 2009 Author Share Posted August 23, 2009 If he hot wires the positive side of the coil this will backfeed the fuel pump relay. The fuel pump will run and the coil will be hot. Engine just may start. Offered to email you an ECU pinout diagram but appears you don't want it. John, I replied on subaruxt forum, my email addy is loonysalmon@gmail.com Link to comment Share on other sites More sharing options...
loonysalmon Posted August 23, 2009 Author Share Posted August 23, 2009 Thank you gloyale, I will get right on to doing that. I charged my battery overnight but it turned out that the battery was completely done for. I'm charging another battery at the moment and hopefully this one isn't toast as well. FSM's have the location of these Ig. relay, FP relay, and Purge solenoid (or just disconnect whole engine harness). I'll have to look around for them however. Thanks so far. And again John, I wasn't ignoring you -Tom Link to comment Share on other sites More sharing options...
Cougar Posted August 23, 2009 Share Posted August 23, 2009 (edited) It all comes down to this. If you don't have power getting to fuse 11 (with the ignition ON) you ain't gots nothin . Edited August 23, 2009 by Cougar Link to comment Share on other sites More sharing options...
loonysalmon Posted August 23, 2009 Author Share Posted August 23, 2009 IT'S ALIVE!!!! Fuse #11 had a loose and/or corroded wire on it--the black/white one. I wiggled it a bit and hooked the fuel pump back up and BLAM... it was alive. Dad says lifter is a bit loud but he has something to remedy that. It's idling at about 500, a bit low if I do say so myself. I LOVE LIFE! I FEEL LIKE A LITTLE KID AGAIN! :banana::banana: YESSS! -Tom Link to comment Share on other sites More sharing options...
Cougar Posted August 23, 2009 Share Posted August 23, 2009 Another happy Soob owner. Isn't life wonderful! Link to comment Share on other sites More sharing options...
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