Announcement

Collapse
No announcement yet.

Curious Mode $06 Failures and Pass Numbers for the Evap and DPFE/EGR Systems

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Curious Mode $06 Failures and Pass Numbers for the Evap and DPFE/EGR Systems

    I have an Autel AL439 code reader/scanner, and it can read limited mode $06 data. I’ve been getting some curious failures and pass numbers for the evap and DPFE/EGR systems, though no codes have ever been triggered and I haven’t noticed any obvious symptoms. I've set out below the readings from three occasions in May 2014, one occasion in late 2014, and one occasion in spring 2015. I used periods to space things out properly since spaces get removed. The stated min and max values for any particular test are always the same unless otherwise noted.

    EVAP:

    Initial Tank Vacuum Reading (max limit)
    ID() .......... 00
    MOD() ...... $10
    TEST() ..... -1494.533 ..... -1743.622 ..... -15692.601 ..... -1494.533 ..... -1743.622
    MIN() ...... -1743.622
    MAX() ..... -1494.533
    STS() ........... OK ............... OK ............... Fail ............... OK ............... OK

    Leak Check Vacuum Bleedup (0.040 test)
    ID() .......... 00
    MOD() ...... $10
    TEST() ..... 249.089 ............ 0.000 ....... -15692.601 ....... 249.089 ......... 0.000
    MIN() ......... ---- ................. ----- ............. ---- ................ ---- ............. ----
    MAX() ...... 498.178 .......... 498.178 ....... -3736.334 ....... 498.178 ........ 498.178
    STS() .......... OK .................. OK ............... OK ............... OK ............... OK

    Test $2A Data
    ID() .......... 00
    MOD() ...... $10
    TEST() ...... 0000 ........... always the same
    MIN() ....... 8700
    MAX() ........ ----
    STS() ......... Fail ........... always the same

    Vapor Generation Max Absolute Pressure Rise
    ID() .......... 00
    MOD() ...... $10
    TEST() ... -15692.601 ..... always the same
    MIN() ....... 996.356
    MAX() ......... ----
    STS() .......... Fail .......... always the same

    DPFE and EGR:

    Delta Pressure for Upstream Hose Test
    ID() .......... 11
    MOD() ...... $10
    TEST() ..... 1494.533 ..... -249.089 ..... -249.089 ......... 0.000 ......... -249.089
    MIN() ........ 0.000 ........... 0.000 ...... -1743.622 ..... -1743.622 ..... -1743.622
    MAX() ......... ---- .............. ---- ............ ---- .............. ---- .............. ----
    STS() .......... OK ............... Fail ............ OK .............. OK ............... OK

    Delta Pressure for Downstream Hose Test
    ID() .......... 12
    MOD() ...... $10
    TEST() ...... 1494.533 ..... -249.089 ..... -249.089 ......... 0.000 ......... -249.089
    MIN() .......... ---- .............. ---- ............. ---- .............. ---- .............. ----
    MAX() ........ 0.000 ........... 0.000 ........ 1494.533 ...... 1494.533 ...... 1494.533
    STS() .......... Fail ............... OK .............. OK ............... OK ............... OK

    Test $45 Data
    always passed and not unusual so not included

    Delta Pressure for Low Flow Test
    always passed and not unusual so not included

    Commanded EGR Dutycycle for Low Flow Test
    ID() .......... 30
    MOD() ...... $10
    TEST() ....... 89.57 .......... 75.29 ............ 49.95 ........... 52.88 ........... 54.86
    MIN() .......... ----
    MAX() ........ 80.00
    STS() .......... Fail ............. OK ................ OK ............... OK ............... OK

    At one point I had gone through the OBD guide that applies to my model year (http://www.motorcraftservice.com/vdi...f/obdsm00c.pdf) and did internet searches, but I couldn’t figure things out. Here are my concerns/queries:

    1. There’s a consistent failure in the vapour generation test, but I have no idea what this means in terms of parts to check. Any ideas?

    2. The occasional changes in stated min or max values is curious. Is this normal? I did update the program and data file at some point, though I don’t recall when. (I wouldn’t be surprised if there was an issue with the scanner itself since the starting and charging tests have never worked properly, though I guess that’s more of a voltmeter issue.)

    3. Any DPFE/EGR issues seem to be resolved. What I did at some point was use a straw to repeatedly open and close the EGR valve. I did it to the point where I could hear it closing, so I know it was moving. I would presume this would have taken care of any problems with gumming up and/or not sealing properly. What confuses me is that the upstream pressure always equals the downstream pressure. AFAIK, one should be higher than the other. Could there be some kind of latent issue?

    As I noted above, no codes have ever been triggered for these issues, and I don’t notice any obvious symptoms; but, it’s the kind of thing I’d like to correct if need be. Thanks in advance.
    Last edited by IPreferDIY; 07-18-2015, 10:15 PM.

    2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
    mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

    #2
    I believe the vapor stuff involves that box that is strapped to the bottom of the trunk pan, the one that gets ripped off if you drive over a curb. Might be worth looking at that for damage, along with the plumbing into it. I know the fuel cap also has something to do with that system, not sure how bitchy it is though.
    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC grandpa spec white and cranberry

    1984 Lincoln Continental TurboDiesel - rolls coal

    Originally posted by phayzer5
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

    Comment


      #3
      The vapor generation fail you see MIGHT be related to incomplete drive cycles for that particular test. The scan tool may just call it a fail. Don't forget mode 6 is not a hard a fast fail, its more of a tally count of possible trouble spots. Unless X number of consecutive fails occur for a given test, the ecm won't set it as a check engine light and considers it a transient fault.

      If the IM monitor is set for evap, don't worry about it.

      Pressure test, for the test, the same pressure is likely what it is looking for to satisfy test conditions.

      Alex.

      Comment


        #4
        Originally posted by gadget73 View Post
        I believe the vapor stuff involves that box that is strapped to the bottom of the trunk pan, the one that gets ripped off if you drive over a curb. Might be worth looking at that for damage, along with the plumbing into it. I know the fuel cap also has something to do with that system, not sure how bitchy it is though.
        I haven't seen any obvious damage under there. And with the amount of oil that I spray under there, it's not really something I want to mess around with just to have a look-see. I've posted something on CVN, so hopefully one of their tech guys will know exactly what's what.

        Originally posted by GM_Guy View Post
        The vapor generation fail you see MIGHT be related to incomplete drive cycles for that particular test. The scan tool may just call it a fail. Don't forget mode 6 is not a hard a fast fail, its more of a tally count of possible trouble spots. Unless X number of consecutive fails occur for a given test, the ecm won't set it as a check engine light and considers it a transient fault.

        If the IM monitor is set for evap, don't worry about it.

        Pressure test, for the test, the same pressure is likely what it is looking for to satisfy test conditions.

        Alex.
        It passes all the emissions stuff, so I doubt it's a drive cycle thing. I suppose there could be something about the particular times when they're tested, but the consistent fails on the two tests really baffles me.

        2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
        mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

        Comment

        Working...
        X