Welcome to Ultimate Subaru Message Board, my lurker friend!
|Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.
We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!
Serving the Subaru Community since May 18th, 1998!
1996 legacy outback vss code p0500
Posted 24 January 2011 - 09:23 PM
Posted 25 January 2011 - 12:23 AM
AG: DTC P0500
— VEHICLE SPEED SENSOR MALFUNCTION
The speedometer system is an electric type; it uses no
speedometer cable and drives the speedometer according
to electric pick-up sensor (vehicle speed sensor 2).
The speed sensor 2 is installed on the transmission. The
speed sensor 2 sends the vehicle speed signal (8 pulses
per one turn of speed sensor driven shaft) to the speed
detection circuit in the speedometer where this signal pulse
wave is regulated.
The regulated pulse signal (4 pulses per one turn of speed
sensor driven shaft) is sent to the speedometer drive circuit
and odometer (trip meter) drive circuit.
The output signal from vehicle speed detection circuit is
also used in ECM, TCM, etc.
The ECM gets it's info from the combination meter.
I don't have the FSM for 96 though so I don't know exactly which wires you need to check for the proper voltage, resistance, etc.
Edited by Fairtax4me, 25 January 2011 - 12:28 AM.
Posted 25 January 2011 - 10:11 AM
Posted 25 January 2011 - 10:51 AM
Tell me - does your dome light work? I blew a fuse when I unwrapped some e-taped wires from a very naughty radio install by the previous owner. That's when it started doing funny things. I just replaced the fuse (15A the main box under the hood) but then promptly loaned the car out and didn't have time to test drive it. I thought it might be related but then again it might not. Perhaps the radio, some illumination, and part of the cluster is powered from there.... WAG.
Posted 25 January 2011 - 11:12 AM
Posted 25 January 2011 - 11:17 AM
Posted 25 January 2011 - 12:23 PM
Posted 25 January 2011 - 12:33 PM
Posted 25 January 2011 - 01:17 PM
Posted 25 January 2011 - 01:44 PM
I pulled the gauge cluster out to find what was going on, turns out the screws on the back of the cluster that hold the speedo head in, and that transmit the signal to the speedo head, were backing loose.
How it works, the speed from the transmission goes into the speedo head, shows the speed, then converts to a different signal the computer uses. Why it does this is beyond me, but the screw that makes the contact to the ECU was coming loose causing a flaky speed signal to just the ECU. I tightened it up, and it's been fine for thousands of miles.
EDIT: I was just looking more closely over some of the posts on here about weird idle. After the speed signal to the computer dropped to zero, if I pushed in the clutch to coast down a hill, come to a stop, etc. The engine would just die. So maybe with an auto that could cause funny idle.
Posted 25 January 2011 - 06:19 PM
Thank you for that info and quick reply? So should I be looking for sensor #1, since my speedo works fine? I think I have located sensor #1 but I wanted to be a little more confident before replacing it since those sensors cost so much. Also has anyone ever heard of a speed sensor causing an intermittent rough idle?
Well the FSM references speed sensor #2 specifically for that code.
On MT trans the VSS2 is on the right hand side of the transmission, right about midway front to back of the trans case.
AT vehicle the VSS2 is on the right hand side of the transmission case, about 8-10" back from the bellhousing, near the top of the case.
The input signal from the speed sensor to the instrument cluster is an 8 pulse per second AC voltage signal. The output signal from there to the ECM is 4 pulse per second DC voltage of 5V. The ECU pinouts changed a few times over the years. I don't know if the 95 and 96 are the same, but you can try checking Pin 57 on the ECU connector for a 5V reading while driving. It may be easier to put the car on 4 jack stands and "drive" it in the air than to try and monitor a VOM while driving on the road. Pin 57 is the first pin on the left in the center row on the right half of the ECU connector.
Posted 25 January 2011 - 06:38 PM
i would look for a bad connection between the speedo and the ECU. if the screw on the back of the speedo as mentioned above is the problem all the better. but if not i would check / clean all of the connections on the ''perimeter'' of the cluster. they are not your typical wire/ plug connectors. if you have ever pulled an instrument cluster you know what i mean.
but having read the post above about the screw, i would check that first.
if the speedo works, the VSS2 and wiring between the two is ok. the problem has to be after the speedo and before? the ECU.
Posted 25 January 2011 - 06:43 PM
Posted 25 January 2011 - 06:57 PM
Is the VSS signal to the ECU one that I can monitor through the OBD-II? I am awaiting delivery of my new OBD-II to Bluetooth adaptor so I can use my Android phone as a real-time monitor, etc.
I have a scangauge. Yes, you can monitor in real time what the ECU is getting for a speed signal. That's why I was saying in my earlier post how I found out where the problem was. I had a good signal to the gauge, but a bad signal to the computer.
Posted 25 January 2011 - 07:31 PM
Posted 25 January 2011 - 07:33 PM
Oh! Excelent. I am definitely going to try that out. An excuse to use a new tool! I'm in.....
Any excuse to use a new tool!! I love new tools.
Posted 25 January 2011 - 08:50 PM
Posted 26 January 2011 - 10:47 AM
Posted 26 January 2011 - 10:52 AM
Hey, so I took out my speedo and sure enough there where five screws that hold the speedo head and they were all about a half turn loose, when all the other screws were snug tight. I started her up and she idles perfectly! Ive only driven twenty miles since and the light hasn't come on yet. It use to come on after about three miles. Ill drive it more today and see what happens and report back. This could have been really expensive if I would of given it to a mechanic. Thank you 987687 for your post and everyone else for all your help. This forum is a life saver!
You're welcome. Glad I could help.
Posted 26 January 2011 - 12:49 PM
Once again you've shown that USMB is the best resource a Subaru lover can have!
Posted 26 January 2011 - 04:23 PM
Posted 26 January 2011 - 05:47 PM
Each gauge head is screwed into that back board, the screws hold the gage in place, and give it the signal.
The four that go into the speedo head are the four on the right that are around the black numbers CO92595. Those are the ones I had come loose.
Posted 26 January 2011 - 08:32 PM
Posted 27 January 2011 - 12:16 AM
This should be added to the USRM.
Posted 27 January 2011 - 12:18 AM
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users