Driving along the highway and the car just stops for no known reason. It happened three times on a long trip recently. Had cruise control turned on at the time but this might be just a red herring. Can put it into neutral while still moving and turn the key and it restarts. Have had intermittent trouble with this vehicle since new--sometimes it just wont start. Grind and grind away at it and it goes. I think it is some sort of electrical problem but am just guessing. Any thoughts?
Yes, I can imagine that it is going to be more or less impossible to find. If the fault is not showing how can a mechanic know what to fix? I guess we will just have to live with it, but its a real disappointment--it means we need to change our thinking and realise that we can not consider the car to be reliable. Damn.
There are a few things you can try that aren't expensive. I would change the plug wires, and check the connections to the ignition module, including the ground. They can test the ignition modules. Also, does the car throw a code when it happens?
I wasnt aware of any code display. Didnt notice anything at the time. But we were so freaked out by it happening that I could have missed it. On one occasioin we were in very hilly singlelane each way conditions out in the middle of nowhere in the region of Mt Isa, and I knew there was a huge roadtrain close behind me because I'd just passed it, and the bloody thing concked out. I nearly shat myself. Anyway got it going again before being crushed by the roadtrain. If my wife had been driving at the time it might have been a very different story.
OK, so where does the code show up? When they test the ignition modules would an intermittent fault like this be diagnosed? Appreciate any comments before I take it to Subaru.
'07 car is (should be, anyway) still under factory warranty. I'd take it back to the dealership and make it _their_ problem.
On a vehicle this new, the most likely candidate IMO is an intermittent in the wiring harness.
Start the car, stand on your head so that you can reach up behind the dash, and start moving wires around. Pay particular attention to the large bundle(s) that terminate at connectors thru the fire wall. When you move the bundle that has an intermittent. in all probability the engine will hiccup, or stall. Spread the wire bundle and start again, moving individual wires until you find _the one_.
My reasoning is this:
When the wiring harness is assembled, the connector male and female pins are first crimped onto the prepared wire ends, and then the pins are inserted into the plastic connector blocks. There is a metal tab on the pin that locks it into the connector block once it is inserted far enough.
It sometimes happens that, either because one wire is a tiny bit too short, or due to sloppy workmanship, one pin doesn't get "locked" into place. When the connectors are subsequently mated, the loose pin is pushed back in the block w/o making a secure connection. Normal vibration and/or temperature cycling can then result in an intermittent contact.
FWIW, this can be a major PITA to find, but is easy to fix once you find it; just push the wire/pin in 'til it locks. The wrench at the dealership _should_ know this, and know how to deal with it. Again, I'd make it their problem.
Hope this is helpful.
ByeBye! S.
Steve Jernigan KG0MB Laboratory Manager Microelectronics Research University of Colorado (719) 262-3101
Yeah if there is no meaningful code stored (I might discount some generic misfire code - dunno) I'd strongly suspect the ECU. Seems to me an intermittent from any sensor would throw a code pointing to a wiring or sensor issue. No repeatable/meaningful code - probably means the ECU itself is shutting things down. And I would have a serious discussion with the dealership and/or a regional Subaru Rep. I think I'd begin documenting everything too.
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