nmos Posted September 1, 2014 Share Posted September 1, 2014 I have a 97 Impreza OBS. Yesterday I had pulled off the road and as I was I was getting back on a chunk of loose asphalt hit the underside of the car. I think it hit the suspension just inside of the drivers side wheel but I could be wrong. Everything seemed fine at first, engine ran fine, temp stayed normal and no trail of fluid behind me but about a quarter mile down the road the engine just quit and wouldn't re-start. The starter turns the engine over but not even a cough from the engine. Here is what I know so far: * The fuel pump is not priming when I turn the key to run and there appears to be no voltage at the pump either then or when cranking the engine. * The fuel pump does run if I power it from the cigarette lighter and will happily spit fuel from the fuel filter in this configuration but the engine still won't start. * I don't believe I have spark but it was hard to tell under full sunlight. Can I use a regular 12v test lamp between the coil and ground or will I fry something? * There are several relays that ARE working, the one mounted on the kick panel under the dash, the "Main" relay (brown plug) and whatever that one just below the Main relay (white) that I can feel clicking when I turn the key to run but I don't think the fuel pump relay is activating but it's really hard to get more than just the tip of a finger on it. The wiring for this relay is equally hard to reach but maybe there is somewhere else I can test from? * There is NO check engine on with the key in the "run" position (there should be right?) * The OBD port appears to be dead. It's been a couple years since I've used it but I could have sworn it would light up elm based scanner without the engine being on. * I checked all the fuses except the one marked SRS with the "special" cover over it and they all looked good. BTW should I be pulling that one while I'm fiddling with the wiring under there? Is it powering anything else important? My plan for tomorrow is to have a look at the ecm. I'll attempt to check power and ground for sure and try to find and test the wire for the fuel pump relay. Any thoughts on where I should begin with this thing? Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 1, 2014 Share Posted September 1, 2014 The OBD2 plug should still have power with the key off. I'm not sure of any wiring that would be damaged from below by a chunk of road. Fuel pump relay is grounded by the ECU. Need to double check fuses for the ECU. You might also check for damage to the passenger floor pan. Link to comment Share on other sites More sharing options...
johnceggleston Posted September 1, 2014 Share Posted September 1, 2014 timing belt? unrelated to the clunk? Link to comment Share on other sites More sharing options...
heartless Posted September 1, 2014 Share Posted September 1, 2014 * There is NO check engine on with the key in the "run" position (there should be right?) yes - all warning lights should come on when the key is turned to the "on/run" position. * The OBD port appears to be dead. It's been a couple years since I've used it but I could have sworn it would light up elm based scanner without the engine being on. Engine does not need to be running, but key does need to be turned to the "on/run" position. I think the SRS fuse has to do with the airbag system Link to comment Share on other sites More sharing options...
nmos Posted September 1, 2014 Author Share Posted September 1, 2014 It looks like I found the problem. The fuse for SBF2 was broken. It wasn't blown in the usual way but broken near one of the blades. I would never have been able to tell if I hadn't actually pulled and tested it. These appear to be an oddball fuse (fl30a ?) so I may have to wait until tomorrow (I'm posting this on Labor Day) to get a replacement. Link to comment Share on other sites More sharing options...
nmos Posted September 2, 2014 Author Share Posted September 2, 2014 Not so fast! I replaced the fuse for sbf2 and the car starts but I'm getting several error codes. I've cleared them but they keep returning. The codes are: P0505 Idle Air Control P0141 O2 Sensor Heater Circuit P0443 Evaporative Emission System Purge Control Valve Circuit P0135 O2 Sensor Heater Circuit Any thoughts? Link to comment Share on other sites More sharing options...
nmos Posted September 2, 2014 Author Share Posted September 2, 2014 Ok, so I checked the voltage on the middle pin of the IAC cable and there was no battery voltage as Haynes manual says there should be and it looks like that is powered via the main relay under the dash right below the fuel pump relay. Either that relay has gone bad (unlikely since the fuel injectors are clearly working) or I pulled the wire lose while I had my hand up there trying to get at the fuel pump relay earlier. Link to comment Share on other sites More sharing options...
johnceggleston Posted September 2, 2014 Share Posted September 2, 2014 (edited) P0141 O2 Sensor Heater Circuit P0443 Evaporative Emission System Purge Control Valve Circuit P0135 O2 Sensor Heater Circuit this SCREAMS wiring problem to me. check the 3 main engine to chassis wiring connectors on the rear of the engine, passenger side. have you done any recent work on the car? wiring or the like?? Edited September 2, 2014 by johnceggleston Link to comment Share on other sites More sharing options...
nmos Posted September 2, 2014 Author Share Posted September 2, 2014 johnceggleston : Yep, it turns out all of those codes relate to things that are powered by the main relay via the yellow/red wire and I confirmed that there is no power to that wire with the ignition on "run" however things that are powered off a different set of contacts on that same relay are working. This whole thing started when I was chasing, what turned out to be, a blown fuse (sbf-2). It could be that when these contacts failed they caused the fuse to trip but it could also be that I shorted or pulled out a wire while trying to cram my large size hands up into that small size gap where those relays live.At this point I just want to get that relay & connector out so I can test but there isn't much room and I can't tell how it's attached. I can get one hand on it pretty well and I'm half inclined to just snap it off but I really don't want to break the connector. I'll probably start a separate thread on that. Link to comment Share on other sites More sharing options...
lmdew Posted September 2, 2014 Share Posted September 2, 2014 10mm nut will unbolt the bracket Link to comment Share on other sites More sharing options...
nmos Posted September 3, 2014 Author Share Posted September 3, 2014 Imdew: Thanks, hopefully I'll be able to fit a nut driver in there and get the bracket down into a more accessible position. You wouldn't happen to know how that main relay is attached to the bracket do you? Link to comment Share on other sites More sharing options...
lmdew Posted September 3, 2014 Share Posted September 3, 2014 i think it just slides onto a metal tab. Link to comment Share on other sites More sharing options...
gazzy2000 Posted September 9, 2014 Share Posted September 9, 2014 Hey, I have a similar problem, howd you get on with this? Link to comment Share on other sites More sharing options...
ivans imports Posted September 9, 2014 Share Posted September 9, 2014 Check wire harness at bottom side of fuse box for corroded wires Link to comment Share on other sites More sharing options...
nmos Posted September 9, 2014 Author Share Posted September 9, 2014 Hey, I have a similar problem, howd you get on with this? Ok, the final outcome was that after replacing the relay the new fuse popped again so I started looking around that circuit for shorts and it turns out that the wire (yellow/red) to one of the O2 sensors was rubbing/shorting against a metal bracket in the engine compartment. After repairing that it's running great. FWIW I gave up getting the old relay out and just disconnected the plug and attached it to the new relay. It's also worth noting that even the Subaru dealer didn't have the fuses so I ended getting a bunch as well as the relay from the local U-Pick-It for a total of about $20. One other lesson learned. I made things worse early on. It was a holiday weekend and I couldn't get a hold of proper fuses so I used a larger 60A fuse on SBF2 for testing. That's probably what really did in my relay. I'm going to grab an extra fuse holder for the normal blade fuses and put it in my tool box for emergency use. Link to comment Share on other sites More sharing options...
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