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"POWER" Idiot Light? '90 Loyale Turbo 4EAT


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As title (kind of) says, I am trying to figure out what the POWER light on the dash of my (still new-to-me) '90 Loyale t-wagon with 4EAT means.

 

The light flashes for a couple of seconds after startup, and sometimes under WOT or (near- ?) situations.

 

The car has known engine issues. (And I know how to deal with them; just here in case they are relevant to POWER light.) The x-over is broken, so major pre-turbo exhaust leak. It will start to show boost about 3krpm, so it does get some boost. Also, the rest of exhasut system is leaky. There appears to be a vacuum leak to the interior uses... vent controls and possibly cruise control. I do not know yet if this leak is systemic or local to ventilation.

 

Unfortunately, all I have at present is a Chilton's manual (hate 'em and always have!), and it doesn't say much about anything.

 

Thanks in advance.

 

Pat

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could be the turbo light....?
There is a separate turbo icon and it lights when boosting.

 

This idiot light is in the middle of the instrument cluster, alongside the AT's (vertical) "PRND32" and just above the "1 HOLD" light. Due to its location, I think it might be tranny/TCU related, but this is just guessing.

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Its the "power transmision" light. For the aggresive shift pattern, should turn on solid at or near WOT, but when it flashes at start-up it indicates a problem the last time the car was run. When it's flashing its going to throw the transmision into fail safe mode, untill its restarted, you gotta figure that one out. Fail safe mode isn't quite a mojorly noticable thing, it keeps the center diff locked up, and if your in fwd (via the fwd fuse under the hood) the 3rd gear clutches wont engage...(?) this is what happened on my car any ways, my light flashed and all that when i left my speedo cable unplugged...

 

though there is something faulty with my electrical system, leaving the power light on close to all the time, it'll turn off ocasianaly, but thats a diffrenet problem.

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power power power....ive enver actually driven/rode in an 4EAT of the EA82 era...or worked on on. So...i jsut dont know. :confused:
I'm pretty sure it is a self-oxymoron... that is it is an indication of a problem reducing power. Amongst the maintenance records that I recieved with the car was "customer says Power light..." and they treat it as a problem. They just don't bother to say what it is or how they tried to pursue it.

 

So far, the 4EAT is better driving than the 3AT. Plus it seems to have a nice OD for freeway cruising... can you say 2500rpm at 65mph? Plus it is FT4WD, has an extra gear, and HAS NO STINKIN' GUMMED UP GOVERNOR!!! :banana:

 

But, it is still an automatic... :rolleyes:

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the transmission does not always go into fail safe mode when the POWER light flashes.

 

POWER light coming on when you stomp on the gas or accelerate is normal, that indicates a power mode, basically that the transmission will use different shift patterns for better acceleration. that is normal.

 

first thing to check - there's a shift resistor usually connected by the strut tower. if this is faulty or has a bad connection, you'll get the POWER light. i have mine unplugged because it gives firmer shifts, and my POWER light comes on because of it. but i don't care, because it doesn't affect anything else, just better shifts, less lag. this droppiing resistor could be bad. if you have an extra, swap it out. at the end of this post is a list of numbers indicating the faults - this resistor is not included in that to my knowledge so i'm not sure how it's supposed to work. ALSO - if your POWER light is flashing but the trans doesn't appear to be in "limp mode"...safe mode, whatever you want to call it - in other words it drives fine and doesn't lock the center diff then i would defintely check this resistor. when this thing is unplugged it makes the POWER light blink but doesn't affect any functionality of the trans.

 

also - before doing all of this and after you check that resistor - how is the fluid? how old is the filter? as old as these things are ATF flushes, new filters and transmission coolers are EXCELLENT ideas for anyone that wants to put lots of trouble free miles on an auto transmission.

 

POWER light blinking 16 (or is it 17) times at start up indicates the TCU has a problem with something. POWER light indicates the TCU is receiving one or more signals that it doesn't like. you can coax the TCU to spit these codes out, it's a real pain in the a!!. like turn on ignition, shift to park, do 3 jumping jacks, turn your radio to NPR, drive in reverse uphill for 0.3 miles, remove left tire, shift into 3rd gear, push your 1st hold button, click lap belt and drink 2 bottles of water...

 

here's another thing to try and i'm not going to explain it, just try it. if the POWER light blinks at start up....try this....while the car is running turn the steering wheel all the way to the left or right and drive the car (don't hit anything!) for like 20-40 feet. keep the wheel turned all the way, turn the car off and then try to start it again. it may not blink this time. this will only work if the center diff (transfer clutches) are engaging and your 4WD is locked....and it's a long shot, probably won't work but does sometimes. if it's the dropping resistor or something then it won't.

 

okay here's how it really works...this is going to sound so convoluted and dumb, but i promise this is the the way to read the codes:

 

START THE ENGINE and allow it to warm up for about 2-5 minutes...

Turn ignition all the way off.

1) Turn ignition ON (don't start the car)

2) Check if POWER light comes on (if not, light or circuit is faulty)

3) Turn ignition OFF

4) Shift into "D" range and turn 1-HOLD switch ON

5) Turn ignition ON

6) Shift into "3" range and turn 1-HOLD switch OFF

7) Shift into "2" range and turn 1-HOLD switch ON

8) Depress accelerator halfway (I just tapped mine to the floor once)

 

If the light stays lit continuously, the range switch, 1-HOLD switch, idle switch, or the circuits of any of the above may be faulty. Otherwise you should get 11 blinks (total of 12 if you count the 2 second blink before the items are checked) (pay attention!!!) A "no problem" condition should be represented by 0.1 seconds of light, then 0.9 seconds of off time for each of the 11 things on the list. A problem consists of 0.6 seconds of light and 0.4 seconds of off time. These times are very close, but you'll be able to tell a difference I promise. Quick light is no problem, long light is problem. You'll have to count to see which one indicates the problem!

 

List of items checked...

1) Speed sensor #1

2) Speed sensor #2

3) Throttle sensor

4) Shift solenoid #1

5) Shift solenoid #2

6) Shift solenoid #3

7) Duty solenoid B

8) Duty solenoid C (4WD only)

9) ATF Temperature sensor

10) Ignition pulse

11) Duty solenoid A

 

good luck,

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AARRRGGHHH!!! I am not sure if I even want to know how you found out this info... :lol:

 

Thanks for the response... hope your Typer's Cramp gets better!

 

I am assuming that the flashing of the light at startup (the only noticeable time it has flashed) is a problem indication? I will check this out soon.

 

Regards,

Pat

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Is this Power Light only on Automatics? I have an 89 GL 10 Turbo, originally auto and converted to standard. It blinks when I start it up. I experience quick hesitations when the Turbo kicks in. Could this be related somehow? That there may be some sensor or maybe something in the computer that is for Automatics only that is not liking something that is occuring now that the car is a standard? Just trying to figure the hesitations out. I turned ignition on without starting the car up and power light was solid. I started the car up and and light blinked 16 times, then solid.

 

Thx, Simon

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Is this Power Light only on Automatics? I have an 89 GL 10 Turbo, originally auto and converted to standard. It blinks when I start it up. I experience quick hesitations when the Turbo kicks in. Could this be related somehow? That there may be some sensor or maybe something in the computer that is for Automatics only that is not liking something that is occuring now that the car is a standard? Just trying to figure the hesitations out. I turned ignition on without starting the car up and power light was solid. I started the car up and and light blinked 16 times, then solid.

 

Thx, Simon

What type of automatic? Was it the 4speed? This transmission has an electronic control unit, the TCU, and if it wasn't removed it probably still thinks that its transmission is there and is freaking over the sensor inputs.

 

*edit - Shouldn't cause hesitation. I believe the TCU is not connected with ECU function. - end edit *

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What type of automatic? Was it the 4speed? This transmission has an electronic control unit, the TCU, and if it wasn't removed it probably still thinks that its transmission is there and is freaking over the sensor inputs.

 

*edit - Shouldn't cause hesitation. I believe the TCU is not connected with ECU function. - end edit *

 

Hmmm, okay. Thx for the thought. Thought maybe it could be connected.

Not sure of the type of Auto it was previously. The delays do seem to be connected to temp as it doesn't seem to be an issue when I first start driving the car but then it appears later on when I'm driving. Someone suggested it could be the engine coolant sensor (I think) but my mech said that those hesitations aren't like the ones I am experiencing.

Simon

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yes the POWER light flashing at start up indicates a problem. if it flashes the 16 or 17 times at start up - it is essentially the same as the Check Engine light for the transmission.

 

in the end there's not much you can do to a transmission. best to replace the fluid and filter, install a tranny cooler and make sure you don't have any leaks. there's a few solenoids that aren't too hard to get to throught the transmission pan, but other than that there's alot involved in working on a transmission.

 

it could be benign...meaning you're not causing any problems by driving it and there is nothing functionally wrong with it. mine blinks every time because of the mods i have to the electronics so i just ignore it but i keep an eye on my transmission. the TCU thinks there is a problem, but i know it's okay.

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oh and i have that transmission code pulling saved on my computer...otherwise you would have never seen it! i wouldn't have typed all that out, i have it so i can copy and paste for occassions such as these.

 

now quit reading this and go change your fluid and filter.

I ain't 'fraid of no transmission! :grin:

 

Records show replacement of one of the tranny solenoids... can't remember offhand if it was the duty a or b.

 

Thanks for all of the info!

Pat

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What type of automatic? Was it the 4speed? This transmission has an electronic control unit, the TCU, and if it wasn't removed it probably still thinks that its transmission is there and is freaking over the sensor inputs.

 

*edit - Shouldn't cause hesitation. I believe the TCU is not connected with ECU function. - end edit *

 

I checked with my Mech. and it was the 4 speed. We have disconnected the TCU (as it is now a standard). When you remove the TCU, is there any additional wiring that needs to be done or is it a case of just disconnecting it.

 

Thx, Simon

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I checked with my Mech. and it was the 4 speed. We have disconnected the TCU (as it is now a standard). When you remove the TCU, is there any additional wiring that needs to be done or is it a case of just disconnecting it.

 

Thx, Simon

I have no knowledge regarding this yet... in fact, I can barely spell TCU. :grin:
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