flashing up arrow on my 850 uk. read inside, please

Discussion in 'Volvo 850' started by colin, Dec 11, 2005.

  1. colin

    colin Guest

    hi

    just noticed that my up arrow is flashing on the dash, i seem to have
    no trouble with my auto box, but also the mode light is flashing. in
    the centre console, i have heard that you can first of all clean the
    switch, then if that does not work, replace it, how difficult to
    clean/replace,

    i used to be a mechanic, but a long time ago. so would like to have a
    go, but also do i have to get rid of the error codes, as i have a 1996
    850 and cannot reset from under the bonnet, or have the reset button
    on the dash, ( as i am told some models/years have this) maybe could
    build a obdII interface to reset the codes. my present job involves
    electronics, but have seen no kits in the uk. i have seen
    downloadeable software on some sites.

    any help would be most welcome .

    col
     
    colin, Dec 11, 2005
    #1
  2. First, you need to have the error code read. It may be something that a
    little preventive service can prevent a major breakdowm. Usually for
    minor things, the flashing lights will reset themselves after several
    days. For major things, it is just an early warning that the inevitable
    is coming. The '95 and some '96 transmissions would fail between 80,000
    miles and 130,000 miles. There should be lots of rebuilt transmissions
    available now and some recycling yards (junk yards) may have some newer
    ones.
     
    Stephen Henning, Dec 12, 2005
    #2
  3. I was told by two Boston-area Volvo dealers' service departments that the
    flashing up arrow, combined with the flashing lights on the console, means
    "time to buy a new $4K transmission."

    Some posters to this group believe it means "time to clean or replace your
    $130 PNP switch."

    Who are you going to believe, two certified Volvo service departments or a
    bunch of web geeks?
     
    Robert Lutwak, Dec 12, 2005
    #3
  4. If you read the codes, it tells if the PNP switch is the candidate. The
    PNP switch problem showed itself in my '95 850 when I would shift the
    automatic transmission manually. When I would downshift, sometimes I
    got the error. The Error Codes said something like wrong speed ratio.
    That could have meant it was the input speed sensor, the output speed
    sensor or the PNP switch. In my case it was the PNP switch and it
    usually is. Unfortunately the dealer replaced that last. In my case,
    since it only did it when I was in "3rd" gear, it should have been
    obvious to the mechanic what the problem was. The problem was that the
    "service writer" never told the mechanic it only occurred in "3rd" gear.
    When a "service writer" starts diagnosing or is too lazy to type in what
    the customer reports the problem to be, that is a big problem. The
    mechanics are highly trained, the "service writers" aren't. My
    dealership goes through "service writers" on a regular basis. The
    mechanics stay.
     
    Stephen Henning, Dec 12, 2005
    #4
  5. colin

    Mike F Guest

    Not to mention, the "bunch of web geeks" have nothing to gain by giving
    you advice to drop 4 grand on a tranny (or not) without diagnosis,
    whereas the "two certified Volvo service departments" do. Also
    generally when there's an internal transmission fault, there's
    noticeable problems with the way the transmission is functioning, when
    the light is on and the transmission seems to be working fine, the
    problem is generally electrical.

    --
    Mike F.
    Thornhill (near Toronto), Ont.

    Replace tt with t (twice!) and remove parentheses to email me directly.
    (But I check the newsgroup more often than this email address.)
     
    Mike F, Dec 12, 2005
    #5
  6. colin

    rd Guest

    I get the flashing up arrow on my '96 850 this time of year here in CT
    (cold and damp conditions). My problem is due to the PNP switch, but
    rather than replacing it (since it only gives the failure when it's
    damp first thing in the morning), I live with the problem. What I did
    was to go into the transmission module under the hood and modify the
    memory chip to not store the fault code (by lifting 1 pin). That way,
    the CE light does not get stuck on and the transmission doesn't stay
    in limp mode. All I have to do is to shut the engine off for a few
    seconds, then restart and I'm good to go with no fault!
    If you leave the fault set, the transmission stays in "safe" mode and
    only runs in 3rd gear.
    It's a poor design by Volvo to have a switch that is subject to
    condensation cause such expensive repairs for unsuspecting owners. I
    wonder how many transmissions were replaced over the years because of
    this stupid switch issue??

    Replacing the switch is fairly easy, but I refuse to shell out good
    money for a once or twice a year problem.

    Bob
     
    rd, Dec 12, 2005
    #6
  7. colin

    colin Guest

    thanks for that, i think the problem is electrical, as my auto box
    changes perfectly, no sticking in gears ect.the box changes gear no
    problem, just the lights on. is the module in the pnp switch ? and can
    i get at it easily?

    col
     
    colin, Dec 12, 2005
    #7
  8. That is not the way my '95 850 works. If I shut off the engine for 2
    seconds and restart, even if I keep coasting at highway speed in
    neutral, the transmission goes out of limp mode and everything works
    normally. In a couple days the yellow light goes off by itself. Of
    course now that I fixed the PNP switch, it never comes on anymore.
     
    Stephen Henning, Dec 12, 2005
    #8
  9. colin

    rd Guest

    Sounds like the problem in my car. The transmission module is along
    the passenger side fender well, in a covered box. Lift off the cover
    and you will see 2 units. If I recall, the one closest to the fender
    is the tranny module. Be VERY careful messing with this unit as they
    are $$$ to relplace. I have quite a bit of electrical experience
    soldering surface mount components. The part you are looking for is an
    8 pin SOIC NVM EEProm chip. If you can understand this, than you will
    probably be ok if you are comfortable with surface mount soldering.
    You will need to either lift or snip the write enable (WE/) pin on the
    chip.
     
    rd, Dec 13, 2005
    #9
  10. colin

    rd Guest

    On my 96 I get a constant CE light cause the transmision module stores
    the fault. The problem is that you can't reset the CE fault with a
    normal OBDII reset tool as with a normal emissions problem, since the
    fault code is coming from the transmission module. You need the Volvo
    reset tool to reset the transmission error code. Otherwise there would
    be no need to modify the tranny module to not store the fault. I still
    get the CE light and limp mode, but it goes away when the car is shut
    off.

    You probably have a different problem if you are getting the CE/limp
    mode at hiway speeds. Mine ALWAYS happens on the first shift (into
    reverse) coming out of the garage in the morning. After that, it's ok.

    Another "trick" I learned from a Volvo tech is (with the car off!) to
    move the shift lever through all the positions about 30-40 times. This
    wipes the contacts clean on the PNP switch.

    Bob
     
    rd, Dec 13, 2005
    #10
  11. colin

    colin Guest

    thanks bob, i will have a go at moving transmission lever, see if it
    clears.

    col
     
    colin, Dec 13, 2005
    #11
  12. colin

    Doug Warner Guest

    Those wer ethe symptoms on my 94.. Shifts perfectly, usually comes on
    when I move the lever.
    One way to test: Before starting, run the lever through it's full
    travel 5 or more times. This wipes the contacts, hopefully pushing
    any contaminants aside (The switch is filled with grease)
    If it fails less often after doing this, it's the PNP switch.

    Not too hard to get at, but you need an alignment tool to get the
    switch body aligned with the neutral detent on the transmission
    control shaft.
    I made one from acrylic plastic that fit over the flats on the shaft
    and indicated the center line between them.

    The hardest part was removing the switch connector. The switch wires
    end at a plastic connector block that fits into a larger connector
    assembly that;'s bolted to the transmission housing, It shares this
    space with another block that probably carries the rest of the trans
    interface. It was a real pain to unlatch the block and work the
    wires through the grommet.

    Instructions and pics here:
    http://www.volvospeed.com/Repair/pnpswitch.php
     
    Doug Warner, Dec 14, 2005
    #12
  13. colin

    colin Guest

    hi
    i did move the lever about 20 times last night, and guess what the
    light has gone off, i did think it would stay on as it maybe logged an
    error code, so will keep fingers crossed, if happens again i have
    printed the instructions off the volvo speed site, and will have a go
    at repair/clean

    thanks for all the help.
    col
     
    colin, Dec 14, 2005
    #13
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