Interesting Electrical Problem

[mattske]

Hey guys,

I'm here to tell an interesting story about a problem that is, as of 9pm tonight, still not solved, but I'm getting closer.

I picked up an 03 GEN4 Wagon a fortnight ago and everything was fine - running great, went for a nice run down through the national park on the Saturday, down to Woolongong, back up and out west, it was sweet.

The next day, I came to an orange traffic light which I didn't particularly want to stop at, so I put my foot to the floor, and as boring as the NA 2.5 Auto can be, something was wrong - if it was a safety camera, I would've been in shit. I arrived at my mates house and didn't think much of it, switched her off and chilled out for a while. Jumped back in the car around an hour later, let her warm up, and went to take off up the road - it felt like I was towing a caravan with the handbrake on... it was slow and revving hard, almost to limiter, but taking a loooong time to get there, and was taking forever to pick up any speed. This went on for the next few days 'intermittently'. There was a strange smell like I'd bee thrashing the hell out of it, like oil burning, however, even though it sounded like it was driving hard, it wasn't.

I did not have CEL, or any other warning lights on the dash.

I did a LOT of research here and other sites, coming up with heaps of ideas and possibilities: timing is off (it's due for it's 200KKm service), knock sensor, MAF, EGR valve, o2 Sensor, bad fuel.. who knows!

I ran a scan with FreeSSM and RomRaider, and returned codes:
P1718 - AT CAN communication circuit
P0724 - Brake Switch "B" Circuit High

My research lead me to these posts -

http://www.subaruforester.org/vbulletin/f95/cel-codes-p0200-p1718-usdm-06-a-7578/ - messing with the wiring of the Trans Temp guage (AT CAN sender?) So I'm thinking that there's an issue with this sender...

I start to think back over everything that's changed since I've bought it - I removed the tow-bar, however there was no wiring loom to be found, to check if it's grounding out somewhere. I put an LED interior dome light in, in place of the old dead dud. I had a car charger plugged into the cigarette socket... nothing too crazy. Also, one of my headlights is out, so I've been driving it around on Parkers + Fogs since I noticed the other day... right around the time that these issues started occurring...

Then my mate calls me to tell me he was following me, and my brake lights were on constantly... So I keep searching, which leads me to the following -

http://legacygt.com/forums/showthread.php/brake-pedal-triggering-dash-lights-and-parking-lights-127217.html?t=127217
http://www.subaruoutback.org/forums/66-problems-maintenance/37561-weird-dimming-problem.html

Turns out my dash and interior lights are doing weird shite, too.

So I decide to have a few test runs... On video! (Please forgive my weird, nerdy voice... I sound like I'm doing a science experiment!)

Test Run 1 - Lights On - http://youtu.be/HMCnNFNXb-k

Test Run 2 - Lights Off - http://youtu.be/UQ7JFBTDfPI

Interior Lights - http://youtu.be/mBfUK7xD0xY

Test Run 3 - Lights Off / On / Off - http://youtu.be/ynuQqUeRVSw

(Edit: Youtube Links)

[mattske]

So I'm hoping that ALL of this ridiculousness and a week of drama, is really just down to missing a headlight globe, which will be arriving tomorrow, and will all be resolved when I pop the new babies in. Otherwise I just can't drive (fast) at night!

Which brings me to my last few 'test' videos... PLEASE NOTE: ALL THESE TESTS WERE PERFORMED ON PRIVATE ROADS

Night Run #1 - crap video!
Night Run #2 - http://youtu.be/FfMUECrQBDY
Night Run #3 - http://youtu.be/qtd7IBxl0XY

Has anyone seen this weird issue before?

Off the record, someone at Subaru said its unlikely to be EGR or MAF, not too concerned about towbar wiring, but that bad fuel would be a likely cause. When I called back with the updated info I've been testing with the lights, they said sounds like the alternator has had it...

[wayner]

Does the problem clear if you pump the clutch? My son's Outback had a problem with the hill holder coming on when the car nose lifted as he accelerated.

Wayne

[mattske]

It's an Auto Wayne.

I've just received my new headlight globes, and managed to lose the retainer spring that holds the globe in place, somewhere down in the deep dark depths of the engine bay... Subaru, of course, don't sell this part, and it's $780 for a headlight assembly! LoL.

Searching wreckers currently..

[SegR]

You have all the luck. Did you snap off the plastic bit which holds the clip? if not, be damn careful and don't! It is a known fragile part and bad design.

[mattske]

You have all the luck. Did you snap off the plastic bit which holds the clip? if not, be damn careful and don't! It is a known fragile part and bad design.

Haha No I didn't SegR, luckily - I did see that when I was researching the clip that a LOT of people manage to snap the plastic, so all good there.

Just got home from picking up the retainer clip from a guy down the road who was wrecking one, $10 for the clip - managed to fit it all back in place, all OK.

I realised only when re-installing it, that you don't need to take the screw out to remove the clip (I did it backwards )

So, now we're getting somewhere - two brand new Osram Rally 65 Watt H7 globes in, looks great - but it didn't solve my acceleration problem. Everything is exactly as it was prior... Poor accel. as soon as i switch the headlights on at all (parkers, normal or fulls), but warp speed with lights off.

[Brunsy3.0]

Any issues starting the car? Couldnt hurt to check the battery condition and alternator charging. Seems weird its only when lights are on. Check if any wiring has been tampered with, repaired or upgraded parts installed that could be connected wrong etc

Do the lights work properly?

[lump_a_charcoal]

I heard about a limp home mode that comes on when brake lights are out - could this be related?

[SegR]

Also this is a shot in the dark and I would only expect it to impact lighting and the BCM, not driving performance, but try removing all non-stock LED lighting.

[mattske]

Any issues starting the car? Couldnt hurt to check the battery condition and alternator charging. Seems weird its only when lights are on. Check if any wiring has been tampered with, repaired or upgraded parts installed that could be connected wrong etc

Do the lights work properly?

No issues starting. Lights, when switched on, work fine. When the headlights are off, when I press the break pedal, my parkers and I believe my indicators come on, as well as the stereo lights in the car, and the instrument panel fades.

[mattske]

I heard about a limp home mode that comes on when brake lights are out - could this be related?

As far as I'm aware the brake lights are OK, I'll go down and check them.. tricky doing it with one person in the rain!

Also this is a shot in the dark and I would only expect it to impact lighting and the BCM, not driving performance, but try removing all non-stock LED lighting.

Only thing is the dome light i replaced with LED, and I'm sure I tested with/without and it was same. I will give it another go now.

A few people now have said alternator... Can someone suggest how I can check alternator and battery voltages etc. I have a multimeter!

*EDIT: break / brake

[mattske]

We have a winner!!

I heard about a limp home mode that comes on when brake lights are out - could this be related?

I had actually read this on another forum / post somewhere, but IMO brake lights were okay, although a friend did say they were staying ON all the time...

I just checked the brake lights which at first glance seemed to be OK, however I decided to pull the assemblies out and check the globes close up.



My drivers side brake light globe was in fact burnt out, and was causing a short across the twin filaments in these bulbs. As you can see very closely in the below pic, where the curly filament meets the straight thick filament, there is a little collection of 'metal fluff'...



So I went to the shop and bought two brand new replacements, fitted both sides, and now everything is A-OK!



Thanks everyone for your responses... What a ridiculous run around, trust me to start with the hard stuff first, instead of the easy ones! I'm just glad it's not something more major... have my 200,000 service in less than 1000kms!

[Brunsy3.0]

Glad you got it sorted champ and extremely happy you posted the results as will no doubt help someone else out in the future. How little it takes to cause a big drama. I think also that you could remove bulbs from inside the boot without removal of entire light assembly but then again I have a sedan and car manufacturers dont like to make things easy

[lump_a_charcoal]

We have a winner!!

I heard about a limp home mode that comes on when brake lights are out - could this be related?

Awesome!

[mattske]

Glad you got it sorted champ and extremely happy you posted the results as will no doubt help someone else out in the future. How little it takes to cause a big drama. I think also that you could remove bulbs from inside the boot without removal of entire light assembly but then again I have a sedan and car manufacturers dont like to make things easy

Thanks mate, and it's my pleasure! Given the amount of reading and stupid things I looked at and worried about, if my post can save someone else some time, then it's worthwhile

And I'm pretty sure you can't get to the globes from in the boot - all the wiring and fittings sit between the boot well (on the outside) and the plastic mould for the lights, no way to get at it as far as I could see. It's only two plastic screws and two bolts anyway