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.
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.
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