Well, my $300 Impreza has hit the road, and I've noticed some transmission issues. It's a 1993, automatic, 4-speed, AWD.
When I got the car, it had a bad radiator. Because of this, I did not drive it much, but I didn't notice any shifting issues. I replaced the radiator, and in turn lost some ATF through the cooler lines. And now it's acting a bit funky.
When I start the car, the "POWER" light blinks. Then I start driving, and it doesn't shift into second gear until I reach about 4000 RPM, no matter how gentle I am on the throttle. The shift into second is quite rough, as it sorta lurches forward. Then sometimes when it goes into third, it hangs for a second before it actually catches. Every now and again, it won't go into gear, and the engine just freely revs like it's in neutral. Usually if I coast for about 3-4 seconds, it'll go into gear. Shifting into fourth, as well as downshifting, acts normal.
I've done research for the past 24 hours, but haven't found an answer. There have been two or three threads with similar problems like mine, but they were not conclusive.
I read the TCU code, and it comes up with code 31 for the throttle position sensor. I have tested the TPS to what I think is correct. The Chilton manual says to measure resistance between pin 2 and 3, which should be 13k ohm - 5k ohm (closed - wide-open). Mine measures 5k ohm - 1k ohm (closed - wide-open). No dead spots or anything. I tried adjusting the TPS, but the only thing it did was set off the check engine light. The resistances didn't change much.
I back probed the TPS and measured the voltage. The power pin had a solid 5.15 volts, the ground pin had a solid ground, and the center pin successfully swept from 0.5 to 4.5 volts (from throttle closed to open). From what I've been reading, that's correct.
I pulled the fuse for the TCU to reset it. Had the fuse out for about two hours, then put it in and went for a drive. At first start, the power light did not blink. But it still shifted the same way. Now the power light blinks for the same code.
I've read that you can unplug the TCU which should lock it in third gear, but I wanted confirmation as to where the TCU is. Under the dash, I suppose.
Also, in terms of ATF, it's clear. Like, I mean clear. When I undid the ATF cooler lines, red fluid came out. I topped it off with new ATF, but it's clear on the dipstick (very hard to see the fluid). The dipstick is wet up to the full mark, and when I wipe it on a paper towel, it has a pinkish hue to it. I have receipts for a transmission flush about 15,000 miles ago (last October).
Just went for another drive, and found that manually shifting through the gears works better. The 1-2 shift is not as rough and going from 2-3 still hangs a bit, but not as bad.
So yeah, any advice as to what is wrong? I would like to get this fixed, as I'll be getting the registration soon. Thanks!
Edited by jj421, 13 August 2014 - 08:27 PM.