No power to rear wheels, no blinking power light? Help!

[scoobydoo94turbo]

I need some help guys, im stumped on this one, basically I have no power going to the rear wheels, no blinking power light, I checked active and stored codes using the shifter, manual button way.. http://www.surrealmirage.com/subaru/trans.html

I just put this 4eat into my wagon as the trans pump died on the original one, the transmission im now using was from the last wagon I owned and it also had the same issue with no rear wheel drive and no power light, long story short duty c is okay and clutches are fine as its the rear end housing from my original tranny originally from this tranny im using now, I cracked tail end housing 2 years back while replacing duty c so I swapped the housing over...

The issue is obviously within the transmission or transmissions wiring as issue was present in both cars..

No power to rear wheels, no blinking power light, extension housing and duty c have been ruled out..

Some help would be much appreciated!

[Legacy777]

Have you tried putting the gear selector in the 1 position to see if that changes anything?

Does the Power light come on and stay steadily lit for a few seconds when you turn the key in the ON position but not start the engine?

[scoobydoo94turbo]

After dinner I went into a snowy parking lot and attempted the first gear trick as if I remember 1st is 50/50, no difference still only front wheel drive, I also stuck the FWD fuse in to check the light in the cluster and it seems to work.. If its nice tomorrow im going to cut or pull the pin for duty solenoid c and see if it starts binding on turns, if it does ill rig up a switch to get me through winter.. The power light acts like it should with koef (key on engine off) im also going to review the circuitry for the FWD fuse and see if it was shorted if its possible it wouldn't not turn the FWD light on, that's my only idea at this point.. Very disappointing!

[Legacy777]

That sucks! Let us know what you find out when disconnecting the wiring for the duty c solenoid.

[scoobydoo94turbo]

Will do that seems to be the best way to figure this out, if she starts binding then ill have to read more up on the operation of duty c, I assume it runs off resistance or voltage, im a mechanic so I have a really good background with this kinda crap but I work for Chrysler.. Not much help when it comes to Subaru, we do out AWD totally differently.. Thanks for the help so far ill keep you guys up to date on my findings, if anyone else has any suggestions feel free.

[Legacy777]

The way the duty c solenoid works is that without any power applied to it full line pressure will be applied to the rear clutch pack and you essentually have 50/50 power split all the time. When a PWM signal is sent to the solenoid, the solenoid will start to bleed off pressure and reduce the amount of clutch pack lock up. So unless something is funky in the transmission the symptoms would indicate you have 12v or near 12v applied to the duty c solenoid all the time, which is what the FWD fuse does to disable the AWD.

Here's some diagnostic pages from the FSM

http://www.main.experiencetherave.com/s ... _diag1.jpg
http://www.main.experiencetherave.com/s ... _diag2.jpg

[scoobydoo94turbo]

So I have cut the Duty C Solenoid wire at the TCM (B33 connector pin #3 WB wire "white/black" in the c3 connector known as b33)

It just snowed a good 3" here so I backed out of drive way once she was warmed up and proceeded to pull an AWD u turn on my street, seems to be AWD again as the ass end kicked out like it should, power light blinks on start up, duty c code is now present..

Allright so what does this mean? Is the FWD option shorted to 12V in the transmission but at a point were it wont turn on the FWD light?

Do remember I have ruled out extension housing assembly and duty c solenoid, my cars wiring is ok as this exact issues was present in the legacy this tranny originally came from..

Im going to enjoy my 50/50 awd in the snow, your thoughts are much appreciated!

[Legacy777]

So just to clarify this very same transmission had the same problem when in another vehicle, and all you did was swap the trans from the other car into this car?

Did the previous trans that was in this car perform normally?

I'm not sure what to tell you without some more info/diagnostic. I'd be curious to know what happens if you add a potentiometer to the duty c circuit and vary the voltage to the duty c solenoid. I guess my thoughts would be that if the AWD capability drops off vs. a slow decrease that something is probably not right in the transmission, either wiring or clutch packs....however that's just an educated guess.

[scoobydoo94turbo]

"So just to clarify this very same transmission had the same problem when in another vehicle, and all you did was swap the trans from the other car into this car?"

Yes that correct, I think an input to the TCU might be causing duty c output to be 12v causing FWD as if the fuse was inserted, after work I plan to monitor the voltage being sent to duty c solenoid while driving, first gear.... etc it suppose to snow again tonight so would be a great time to monitor the voltage to see..

I will report back with my findings, as of right now I have a switch rigged up to cause an open in the duty solenoid c wire so I can have my 50/50 AWD, sure sux driving around a FWD Subaru!

[Legacy777]

Ok, sounds good....let us know what you find out.

[scoobydoo94turbo]

Ill start by saying, my car is now AWD or it has been for a day and a half, my measurements support my theory and I also had the car running on my hoist, since driving in 50/50 she seems to have cleared up is what im getting at... I sure feel like the center differential is taking way to long to lock up but according to the voltage its trying or it is locking up. I have gone and installed a switch to cause an open circuit as it is a nice mod to have and its my help switch should she go back to FWD again..

Since all of this clearing up my speedometer has also stopped working, I have checked and re fitted the cable twice into transmission, also hooked up a drill and she spun up to 80km/h so cable and cluster are ok, im assuming the cable is not fitting in to the trans properly or something inside the frond diff shit the bed! it was working for a few days after tranny swap, last I also have 2 active codes for speed sensor 1 and 2 (codes 32 and 33) none of this makes any sence to me but hopefully there is an explanation...

Below are my readings before leaving (cold start), while driving and once home from work, im sure these will come in handy in the future for people trying to diag duty c issues.. (manual button did not effect my readings)

Cold Start Measurements
P - 10.9V
R - 4.7V
N - 10.9V
D - 4.8V
3 - 4.8V
2 - 4.7V
1 - 3.5V

While Driving (D and or 3rd gear 40km/h-120km/h)
D - 6.0V-6.7V Coasting
D - 5.4V-6.0V on Acceleration
Voltage would drop on acceleration or spike higher on decal as my readings show

Once Home in Driveway
P - 10.8V
R - 4.3V
N - 10.8V
D - 4.5V
3 - 4.4V
2 - 4.4V
1 - 3.3V

These numbers all seem good to me but, on snow from a stop if I was to acceleration to purposely slip a wheel the voltage spikes down to 2.5V, 0V and back up to about 3.5V, this alarms me as if I understand correctly I should read 0V or real damn close if the center diff is actually locking..

Thank for again for your help with this issue, im happy things with the AWD might be ok, makes no sence as the same issue was present in the original car its from but I have the switch installed should she go FWD again.

[Legacy777]

Did you do the tests on this pages?

http://www.main.experiencetherave.com/s ... _diag2.jpg

I'm curious to see what the voltages are under the first test. Also, checking the resistances of the wiring, ground, and duty c solenoid to make sure they're in spec would be good to know.

Regarding your speedometer issue. There is a metal base piece that screws into the transmission. These are common failure points. It should only be a couple bucks at the Subaru dealer. Pull this out, and with the car jacked up, turn the wheels to see if the output piece in the trans from the speedo gear spins. If it does, then the base piece is just bad.

http://www.main.experiencetherave.com/s ... lebase.jpg

[maopalo]

scoobydoo94turbo any news on the issue? i'm in the exact same situation
Regards,

[Legacy777]

Welcome to the BBS.

What diagnostic steps have you done so far? Have you pulled the codes from the TCU? If so, what were they?

[maopalo]

Thank you Legacy777,
I have done an entire rebuild (banner kit, complete planetary, brake bands, filter) and checked the valve body with compressed aire and seems ok.
I have no tcu codes from power ligth, it powers up normal and goes off when vehicle has started.
It's weird because the duty C solenoid is not stuck, the rear clutch has been replaced, and still no power to rear wheels.
I think i will test the pressure in the back.
Any ideas?

[Legacy777]

If you put the gear selector in the 1 position does that change anything?

I think you're on the right path and should check pressure going to the rear clutch packs.

[maopalo]

I have some news.
The pressure checks ok.
Putting the gear selector in the 1 position does not change anything.
Check out this, with the car on 4 jack stands, the rear wheels start spinning. BUT when 1 front wheel touches the ground, rear wheels stop working
Any ideas?????

[Legacy777]

I wish I had some suggestions, but I don't. I'd say something is not working correctly inside the transmission, but I don't know what it could be.