Subaru Outback Forums banner

1 - 20 of 125 Posts

·
Registered
2001 Outback H6 4EAT | 1999 Impreza GF8 NA Dual Range 5MT
Joined
·
39 Posts
Discussion Starter #1 (Edited)
Hey,

I have been a silent viewer of this forum for years now, learning a lot of things.
Now I am struggling with a problem of my own, to which I couldn't find a solution here.

First, some detail on the car:
2001 Outback (EUDM, left hand drive)
4EAT with VDC
H6 with 154 kw / 206 hp

I am new when it comes to automatic transmissions on Subarus. From day one since ownership I have noticed a very loud buzzing, solenoid like sound coming from the transmission, as soon as I turn the ignition on (engine off).
The sound is altering, when the throttle is pressed.
I have had the ignition on for times as long as 15-20 minutes, and it never went away (so we can rule out any self checking/calibration routine)
It also doesn't stop, when I shift it though the gears (still while the engine is off)
And to answer the last question: The buzzing neighter wont stop, when I turn the engine on.
No CEL or trouble codes.

I think, the video should visualize the matter pretty well


Although the video shows the shift unit at the end, the sound is coming from underneath.

Any thoughts on this?
 

·
Premium Member
03 H6 OBW & 06 WRX Sportwagon
Joined
·
17,961 Posts
pull fuses until it stops, check what item(s) the fuse protects?
 

·
Registered
2003 Outback H6 Wagon VDC EUDM
Joined
·
74 Posts
I have the same car and same issue. I didn't solve the "problem" until now, but I tried some things:

you will need these repair manuals : CLICK

it's also very helpful to get romraider and freessm (there are several threads here)

1- First: it is one of the solenoids in the trans. When you listen carefully under the car
2- Noise comes on, when HOLD mode is on
3- Noise comes on, when TPS is disconnected

What I tried for routing the problem according to the repair manuals:

1- Checked the engine harness underneath the manifold -> no evidence
2- Checked the harness to the ECU -> no evidence
3- Checked the groundings of the ECU -> no evidence
It's called the B83 plug, which can be found right where the ECU is
4- Changed a new TPS -> no change
5- Disconnect ECU completely -> noise is gone
6- Connect ECU back in and disconnect TCU from ECU -> noise is gone
I think it was the line A13 of the TCU plug, but not sure anymore

Because of other recent problems, I had to stop last year. I'm still driving the car with this issue for 6000 miles. It is annoying to know, but it seems to do no harm to the trans.

My suggestions until now is the solenoid of clutch 2, ECU, connections ECU-TCU,....
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
I suggest you check the battery and grounds first.

To check if it's the fuel pump lift the rear seat and pull the insulation cover up to see if the noise gets louder. The fuel pump should only run 2 seconds and then shut off until the engine starts.

Since the noise changed when you moved the throttle I'm thinking pressure control solenoid on the valve body. Does the noise subside or go away once the engine starts?
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
Although the MIL is not coming on there may be codes stored in the TCM and ABS/VDCCM. You have to have a scan tool that will read TCM and ABS codes. FreeSSM will not communicate with this yr model VDC TCM. I've not been able to get it to talk with mine. So you'd have to find someone with a scanner that can.

Still check the battery and grounding.
 

·
Registered
2001 Outback H6 4EAT | 1999 Impreza GF8 NA Dual Range 5MT
Joined
·
39 Posts
Discussion Starter #8
Thanks @Deberius for the thorough reply.
When I disconnect the TPS, the sound is behaving like the throttle isn't pressed at all.

@cardoc I checked via the onboard DTC. There are no stored codes, neighter in the VDCCM nor in the TCM, as far as I can tell. Battery is brand new (and even with the old one the sound was still present), terminals are clean. Grounding is a valid point. Will be checking those.

Since the sound stops, when I pull the driver side transmission connector (B11 (black)), we can narrow it down to one of those parts (although pin 7, 8 and 10 are not described in this chart):

504581


Since I doubt that any of the sensors are causing the buzz, does someone know, which of those solenoids is affected by the TPS?
 

·
Registered
2003 Outback H6 Wagon VDC EUDM
Joined
·
74 Posts
When I disconnect the TPS, the sound is behaving like the throttle isn't pressed at all.
ok... did you try with the hold button?

6 month ago I took a record with romraider and a video. I can't find them at the moment...
In my really dark memorie you could see, when solenoid for gear engages the pressure soloenoid did somthing different.... (or something similiar -> when this happens, sound is coming up

FreeSSM will not communicate with this yr model VDC TCM
mine does, atleast major values....

is the trans pan dented?
in my case no...

@Hayk301 : I don#t want to hijack your thread... 🍻 I'm just happy, That I'm not the only one ;)
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
@Deberius Yours is a 2003, different TCM. There were TCM changes in 02 up. Mine is an 01 and FreeSSM won't talk to it. ROM Raider doesn't see the TCM either. If anyone else with an 01 USDM has gotten either to communicate, I'd like to know how.
 

·
Registered
2001 Outback H6 4EAT | 1999 Impreza GF8 NA Dual Range 5MT
Joined
·
39 Posts
Discussion Starter #13 (Edited)
@1 Lucky Texan no, no "physical" damage anywhere on the transmission
@Deberius kein stress ;)
I am also happy, that there is some experience to be shared. Neighter power button, nor at hold change anything

So a quick update:
I disconnected B11 and hooked each pin together one by one. No buzzing whatsoever. If it would have been one of the solenoids, then I should have been able to reproduce the sound that way. (According to the wire schematic each solenoid works independently, so by applying voltage to each wire, the corresponding solenoid should start working.) I also tried to determine if the TCM is sending some kind of pwm signal, but again no luck. "Stable" 12v to all solenoid pins on the female connector.

Could it actually be possible, that one of the sensors are causing that sound? When I tested each pin one by one, pin 16 on B11 wasn't connected to ground. Might that be the cause, that I couldn't replicate the humming while testing?

Edit: What exactly are those wires and what purpose do they fulfill?
504605

Are there some kind of conductors in between the insulators (much like those cables used in TV and HIFI applications)?
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
You have to have positive and negative current to activate any electrical part.

Those wires are shielded to cut down electrical noise.
 

·
Registered
2001 Outback H6 4EAT | 1999 Impreza GF8 NA Dual Range 5MT
Joined
·
39 Posts
Discussion Starter #15
You have to have positive and negative current to activate any electrical part.
I don't quite get that.
The soleniods are connectet to ground via the transmission ground cable.
So if I put positive current thought one of the solenoid pins (sourcing it from the corresponding pin on the TCM-side connector) the circuit should be closed resulting in the operation of the component.
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
More than one solenoid at a time is in operation at any time the key is on, running or not. The noise may be from a combination of solenoids amplifying to a level you can hear it.

I know the solenoids ground to the case.

Did you check the car's grounds?

Look, I've not had a gen 2 do this. My own, 2 different H6 Outbacks, one VDC and the other a Bean, do not do this. So, in trying to narrow down the issue I make suggestions. If you want to verify any solenoid operation when you jump a pin at the connector you have to be able to determine if the solenoid is functioning by it's click. Doing this requires a stethoscope or a pan drop. And when the TCM sends a pulse to the solenoid, and a solenoid is loose, there's a bad ground, or whatever, the solenoid will vibrate and the action of the solenoid will mirror the current flow.

Start at the basic beginning. Battery and cabling.
 

·
Registered
2001 Outback H6 4EAT | 1999 Impreza GF8 NA Dual Range 5MT
Joined
·
39 Posts
Discussion Starter #17
More than one solenoid at a time is in operation at any time the key is on, running or not. The noise may be from a combination of solenoids amplifying to a level you can hear it.
I have also thought of this. When pushing the throttle, it seems that an other solenoid is causing the change in tone

Do you know, where the grounding points on those transmissions are located? I found one on the upper the transmission mount. But I doubt, that that might be the only one.
 

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
The transmission is grounded by being bolted to the engine. The main ground cable that bolts to the bracket at the starter bolt is the main ground for the engine and transmission. The body ground is a satellite wire off the negative cable and all the satellite wires throughout the engine compartment that go from the engine to the body. The main engine harness ground is the two that are on the intake manifold runner for cylinder 5.
 

·
Registered
Joined
·
18,560 Posts
Is that a 2001 North American Outback, H6, 4AT with VDC? I ask because the wiring diagram posted earlier does not include the dropping resistors for the Line Pressure and 2-4 Brake solenoids that are shown in the North American wiring diagram for that combination (attached).

Based on the North American documentation, the Shift Solenoids (1 and 2), 2-4 Timing Solenoid, and the Low Clutch Timing Solenoid are all on-off, and either get <1 V or >9V, steady, depending on the car's situation at the time. The Line Pressure Solenoid, Lock-up Solenoid, 2-4 Brake Solenoid and Transfer Solenoid are driven by duty-cycle (DC) signals. (See the TRANSMISSION CONTROL MODULE (TCM) I/O SIGNAL table in the AT Diagnostics section of the FSM.)

The TCM I/O table has data on the voltage that should appear at each of the TCM pins for the solenoids when the ignition is at On. The measurement methods are in the Diagnostic troubleshooting pages for each of the solenoids.
 

Attachments

·
Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
15,150 Posts
@plain OM
Judging by the avatar and the GC8 with dual range, it's not North America. I don't have an FSM for other regions and until the OP says otherwise I'm going to assume non-JDM as well.
 
1 - 20 of 125 Posts
Top