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Just got a 95 legacy lsi sedan. FWD light is on, AWD does not work. Can someone direct me to a troubleshooting guide?

 

Speedo is jumpy at low speeds, is there a speed sensor that links to the awd?

 

I read somewhere about removing a fuse, does this keep it in awd?

 

I know I need to do more searching, just hoping for a quicker discovery...

 

Thanks all

 

erik

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On the passanger side of the engine compartment on the firewall, there is a little fuse holder. Take the fuse out of it and that will turn on AWD

-broknindarkagain

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...FWD light is on, AWD does not work. Can someone direct me to a troubleshooting guide?

 

Speedo is jumpy at low speeds, is there a speed sensor that links to the awd?

 

I read somewhere about removing a fuse, does this keep it in awd?

 

 

erik...

 

Check all of your tires & see of they are matching in size & slightly matching in PSI (32 to front/30 to rear).

 

Check to see if there is a fuse in the FWD slot by the firewall on the passenger side of the engine bay. Remove it & drive.

 

During your drive with the FWD fuse removed, 'feel' for any kind of 'binding'...

 

Is there a spare on the car? (spares should go in the rear at ALL times)

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The light is on because the fuse is in there. Take out the fuse (there IS NOT suppose to be one in there) and the light will turn off.

 

Putting a fuse in that spot basically turns off the rear diff. Take that fuse out, and report back with how your car drives

-broknindarkagain

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Because the duty c solenoid is designed to kick on and off....open and closed.

 

When you put the FWD fuse in there, the solenoid is STUCK open....putting more wear and tear on it.

-broknindarkagain

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a couple things. one, IMO the solenoid shouldn't take significantly more damage at 100% duty cycle as opposed to constantly cycling on and off, possibly less(less voltage spikes and vibration etc.). two, as someone who has disassembled my rear transfer housing several times, from the design it shouldn't cause damage if the front and rear are reasonably close in speed. how it works is it is a direct gear drive to the front wheels, with a clutch pack that engages to transfer power to the rear (except the VTD/VDC cars) so with the transfer control valve open, the clutch is open and as long as you are not doing burnouts the small amount of slippage of the clutch shouldn't build too much heat or cause too much wear. this clutch is designed to be able to slip under normal operation.
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obviously the ideal is to repair whatever is causing the problem requiring the FWD fuse. but I am simply saying in my opinion, so long as there isn't a significant difference in f/r speed the clutch should be ok, and as someone who has a reasonable understanding how electromagnetism and solenoids work, i see no reason why it shouldn't be able to run 100%, there are MANY solenoids in your car that run 100%.
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My point is there has to be a reason why Subaru says not to run the vehicle with the FWD fuse in. If the car was designed to be driven in FWD or AWD...it would have a selector switch like 4x4 does

-broknindarkagain

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for one thing they were selling full time AWD. also, it is likely to cover them in case some idiot would get stuck in ice or do burnouts in FWD and damage the transfer clutch. I am not saying it can't damage it just saying I don't think it is likely. if you disagree then don't run with the fuse in. it was't designed to be driven long distances in FWD, and that alone would be enough for Subaru to say not to run it like that, but that doesn't mean that with careful driving you can't drive with it in FWD at least for short trips.. obviously subaru designed it to be driven with the spare on for a certain amount of time.
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4EAT w/o VTD:

Have the FWD Fuse. It can be used for short distances when the temp tire is in place. I you run it like this on a semi-regular basis you will break your tranny. Power split is 80/20 under normal conditions and can go up to 60/40 during slippage, pre-00 4EAT used speed sensors to detect slippage only, post-00 speed, weight and computer pre-emptively splitting power was established. Uses clutch packs to vary torque. When in "1" the ATF line pressure is increased to max pump as well as the clutch fluid pressure, this will give it a faster reaction time according to the factory manuals. Pre-96 4EAT had an initial split of 90/10.

 

5MT:

No FWD fuse, cannot disable AWD via fuse or easy means. Center diffy is viscous and will vary power. 50/50 initial split with up to 80/20 and 20/80 under slipping conditions.

 

XT6 5MT:

Same as 5MT but has manually controlled locking center differential that will lock power in at 50/50 no matter what slippage occurs.

 

4EAT w/VTD:

No FWD Fuse. This has initial split of 45/55 torque and can vary it up to 80/20 and 20/80 during slippage. Uses planetary gears along with clutch packs to vary torque. Also uses speed sensors, weight sensors and computer pre-emptive torque distribution like the 4EAT.

 

4EAT w/VDC:

Same as VTD but adds: Yaw sensors and use of brakes to stop slippage of individual wheels.

 

4EAT w/VTD & Sportshifter:

Same as VTD but adds tiptronic like controls for changing gears.

 

What vehicles have what ATs?

Imprezas/Forester up to 01 had 4EAT w/o weight and Ecu sensors.

Legacy up to 99 had 4EAT w/o weght and ECU sensors.

02 WRX has 4EAT w/VTD

VDC has 4EAT w/VDC

03 Legacy GT has 4EAT w/VTD and Sportshifter

00->03 Legacy and Outbacks have 4EAT w/ weight and ECU sensors

88,89,91 XT6: 4EAT w/o weght and ECU sensors or 5MT w/Locking center diffy.

 

4EAT non VTD/VDC units have electronically controlled clutch packs (3)

4EAT VTD/VDC units have electronically controlled clutch packs (6) plus a planetary gearset.

 

Manual Button, and Power Light:

 

Vehicles with "power" mode light can engage "power" mode when you hit the accelerator quickly, even if you are in the "2" "3" or "D" positions, this will raise your shift points to redline.

 

Vehicles without the "power" light do the same thing, except there is no light to indicate this.

 

If you have the "manual" button on your car, then you hit the manual button and place the car in "2" or "3" and the car will be held in that gear regardless of where the 4EAT thinks it should be.

 

Vehicles w/o the "manual" button, you can start out in 2nd gear by placing the shifter in the "2" slot, this will start you in 2nd gear and bounce you off the rev limiter.

 

I recently took my '92 SVX to Limreock Park for a track day. I tried several different combinations of gear slections. Finally settled on "2" which kept me in 2nd gear most of the track, when I hit the straightaway, it hit redline and upshifted to 3rd.

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all it says is if you use it on a semi regular basis you will "break" it.

1. Who is posting this and where did he get this info, is he still parroting what Subaru says?

2. How will it break it? what will break?

as i said, I have become quite familiar with the internals of the transfer housing. I am not the designer of the system, so obviously i could be completely wrong. but i see nothing that would sustain damage under normal driving with proper inflated tires etc.

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As I understand it, at least in an automatic, the power split is 90/10 front/rear except under hard acceleration, when the power is split 50/50. So, clearly, the front end of the car was never intended to receive 100% of the engine's max power at any point. My theory would be that as long as you are not heavy on the throttle, it is not likely to cause damage.

 

That theory was backed up when I talked to S.O.A. who said that the front driveshafts were not engineered to take 100% of the engine power and that it was a possibility that you could twist them. I'm more likely to believe that is an over-exaggeration in order to cover their asses, but I'm still sure the car was never meant to channel 100% of the power through the front all the time.

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As I understand it, at least in an automatic, the power split is 90/10 front/rear except under hard acceleration, when the power is split 50/50. So, clearly, the front end of the car was never intended to receive 100% of the engine's max power at any point. My theory would be that as long as you are not heavy on the throttle, it is not likely to cause damage.

 

That theory was backed up when I talked to S.O.A. who said that the front driveshafts were not engineered to take 100% of the engine power and that it was a possibility that you could twist them. I'm more likely to believe that is an over-exaggeration in order to cover their asses, but I'm still sure the car was never meant to channel 100% of the power through the front all the time.

 

the front axles on the SVX are the same units as on the other subies. the SVX was available in FWD and had 230hp. your idea had merit but i don't think that is the issue.

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Just got a 95 legacy lsi sedan. FWD light is on, AWD does not work. Can someone direct me to a troubleshooting guide?

 

Speedo is jumpy at low speeds, is there a speed sensor that links to the awd?

 

I read somewhere about removing a fuse, does this keep it in awd?

 

I know I need to do more searching, just hoping for a quicker discovery...

 

Thanks all

 

erik

 

as stated, the FWD light is on because the fuse is in the FWD holder. remove the fuse and see how it drives. you will probably find that it has torque bind.

 

 

the speedo being jumpy is probably due to the front speed sensor going bad. if it fails all together, you will not have AWD. the system needs both speed sensors to compare in order to be effective. if one fails you end up with FWD only. but you will not get a FWD lite because of it.

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So is it possible for that front speed sensor going out to cause drivability issues? I really don't know, I haven't come across a bad one on an AWD car yet. This may be why the FWD fuse is in.

-broknindarkagain

My Current Project - Click Here

COME AND TAKE IT

"The only thing necessary for the triumph of evil is for good men to do nothing."

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