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Power Light Blinks Intermittently
Posted: Fri May 30, 2008 4:17 am
by James614
It first happened after driving about 15 miles on a rural highway, the power light would come on for a second, and the torque converter would unlock at the same time. It kept doing that every minute or so until I pulled into a gas station to check the fluid (seemed normal, full and healthy pink). I bailed on our trip and headed back, and it did it again, this time falling out of overdrive when the power light came on, and the light stayed on for 3 - 5 secs. It only did it twice on the way back, and it's been acting fine ever since.
The procedure for checking TCU codes is to drive the car and leave it on with the engine off, right? I did that and didn't see any flashing.
Posted: Fri May 30, 2008 5:04 am
by skid542
Is your power mode override switch glitching out on you perhaps? I assume you still have it installed?
Posted: Fri May 30, 2008 1:03 pm
by James614
I thought of that last night, and spent a few minutes checking it out. Seems to work perfectly still. I'll pull the wires out anyways for a while to see if it happens again.
Also, I was thinking it may be a trans temp issue, but I towed my dad's Jetta last night for a few miles and it didn't give me any issues then
Posted: Wed Jun 25, 2008 12:07 am
by James614
Ok, so after weeks of problem free driving (nothing more than 9 miles though), I drove 50 miles yesterday to have the problem return with a vengence.
The nature of the problem actually seems to be trans behavior similar to if I were to just keep stomping the gas randomly. It downshifts and goes into power mode, for no reason, but the trans seems mechanically fine.
My thought was the TPS, or the TCU. I can check the tcu by swapping with my wife's car to see it the problem follows it. Another shot towards it possibly being the TPS is that the phantom shifting is sometimes accompanied by roughness in the engine. But where's the tps and how would I test it?
Posted: Thu Jun 26, 2008 11:59 am
by b3lha
It does sound like a TPS fault.
It's a black plastic box attached to the throttle body at the back of the inlet manifold. It's just a fancy type of potentiometer.
There are some interesting diagnostic tips in these threads:
http://www.subaru-svx.net/forum/showthread.php?t=43333
http://www.subaru-svx.net/forum/showthread.php?t=1799