2002 V6 - SES Light - No Codes Can Be Pulled

Discussion in '1994-2004 V6 Mustang Tech' started by 08'MustangDude, Jan 31, 2018.

  1. 08'MustangDude Active Member

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    Basically, the SES light is on. Scan tool says 1-code stored, but when you
    READ codes, it says none found. Won't reset, and sometimes the tool won't
    connect at all. Other times, the tool will lose Coms with the ECU, and you have
    to start over again, and again, till it connects.

    Previous owner says he forgot to mention it... Also said it's been that way
    for 7+ years. He has taken it to many places, whom all have failed to pull
    an actual code from it, and has been able to CLEAR it, but then it comes
    back on, same thing, 1 stored, none found upon read.

    Car is in great shape for a 2002, immaculate interior. Was owned by a police
    officer, garaged and well kept after. It's been exempt from emissions under the
    < 5000 mile rule here in PA, but I am sure more than that many miles will be
    put on it now. In PA, it fails emissions with a SES light on, regardless, unless
    you're in a county that does not have emissions. It won't be due till July '18.

    Anyone ever have this issue? I read only few ECU glitches that have caused
    something similar.
     
  2. six gun Active Member

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    I have had a similar situation in my 1999. There's been a handful of times I've hooked my old tuner up that has a diagnostic tool and it can say "no codes found" even with the SES light on. Been a problem since I installed long tube headers and aftermarket catalytic converters. Well eventually I've pulled codes for catalyst efficiency on either bank, it must just barely fail once in a while because wrong cats, whatever.

    I live in South Dakota where there is no emissions testing, so what I did was use spark plug non-foulers to space the rearmost oxygen sensors out of the main exhaust stream, and have since not had catalyst efficiency codes come up. Several months now.

    So its a chance you may have some failing cats, but that's just speaking from my experience.
     
  3. 08'MustangDude Active Member

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    The 2002 has no mods at all, but will look into the cat thing. There is
    an exhaust leak that was not there when we bought it. My son decided
    to open it up to 100MPH, and that probably opened up any weak spots
    in the exhaust. Still, the owner prior said it has been going on for 7+
    years, and no one has been able to pull a code.

    Thanks for the reply.
     
  4. 6 Shooter Well-Known Member

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    One way to clear the hidden codes is to disconnect both battery codes from the terminals and clamp the two battery cable ends together for about 5 minutes which should clear those hidden codes, but not change the PCM tune.
     
  5. 08'MustangDude Active Member

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    The code AutoZone pulled: P1285 - Cylinder head over temperature sensed.
    Reservoir for the coolant reservoir was bone dry. I guess a coolant pressure
    test is needed... The temp gauge on the car never went into the hot, but it
    varied while driving. The reservoir was filled, and my son says the temp gauge
    has not been moving. So, will have the coolant system pressure tested...
     
  6. 08'MustangDude Active Member

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    Okay, more on this. I let it idle for about 20 minutes, and the temperature
    gauge moved to just above half. Hoses and rad were still cold. Eventually,
    the cooling fan kicked on, but the rad and hoses were still very cold. I
    opened the rad cap, coolant sprayed out, but was cold. So, my guess
    is thermostat... I plan on replacing it, but with what temp? 180 or 195?
     
  7. six gun Active Member

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    Hoping you didn't break a head gasket.. Either temp thermostat is good. I use 180° myself
     
  8. 08'MustangDude Active Member

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    He took it out, was going to the store, and this time it did over-heat,
    went into the red, and coolant was all over the engine compartment;
    from the over-flow bottle. Has to be the T-stat, right? I blew into the
    rad to engine hose, and got coolant from the top block side, and splash
    from the fill neck. Man, I hope that's all it is, or $2700 down the crapper.
    I got the job started, but lost light, and it's just way too damn cold out
    to be out there more than 40 minutes.
     
  9. 08'MustangDude Active Member

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    I boiled some water, and put the thermostat in it, and it did not open.

    Went and got a 180-degree one, will try and get it in tomorrow. Started on it
    but we lost daylight, and is just to cold out...
     
  10. 08'MustangDude Active Member

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    I should have followed the directions for the T-stat to the letter.. It was
    so much harder doing it with the housing attached to the hose, and it
    was too cold to take off, would not budge.

    But, I got it on, with the gasket, how long should I wait before adding
    coolant and starting it up?
     
  11. 08'MustangDude Active Member

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    Thermostat did the trick...
     
  12. six gun Active Member

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    That's good, I had no good ideas myself anyway ha. Could've been much worse.
     
  13. 08'MustangDude Active Member

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    CES light is off now, reset on its own.