Need help understanding ignition module protocol
Posted: Sun Mar 10, 2013 5:31 am
I am trying to understand the communication between my ECU and my ignition module. 96 Ford Aspire (kia/mazda) here - ignition coil is inside the distributor.
With a logic analyzer I see my CKP sensor sends four pulses per camshaft revolution and four pulses on the sparkout wire coming from the ECU. I am hoping to extract ignition advance data from the comparison of these two signals.
What could be the physical sense of the spark out signal? These signals are around 4ms wide. Is it the time needed to charge the coil, and the spark occurs on the level fall? This case the signal is CHARGE/FIRE. I hope it is not something like the Ford EDIS with it's 'advance pulse' protocol.
I've noticed that the pulse width is about 3.7ms in the 1500-5000 rpm range, but it is up to 7ms long for lower RPMs. If that would be just the charge/fire, what would be the reason for the pulse width variation?
Here is a chart of the sparkout pulse widths for different RPMs:
Here is some data from my log, I will try to attach the log:
With a logic analyzer I see my CKP sensor sends four pulses per camshaft revolution and four pulses on the sparkout wire coming from the ECU. I am hoping to extract ignition advance data from the comparison of these two signals.
What could be the physical sense of the spark out signal? These signals are around 4ms wide. Is it the time needed to charge the coil, and the spark occurs on the level fall? This case the signal is CHARGE/FIRE. I hope it is not something like the Ford EDIS with it's 'advance pulse' protocol.
I've noticed that the pulse width is about 3.7ms in the 1500-5000 rpm range, but it is up to 7ms long for lower RPMs. If that would be just the charge/fire, what would be the reason for the pulse width variation?
Here is a chart of the sparkout pulse widths for different RPMs:
Here is some data from my log, I will try to attach the log:
Code: Select all
ckp start ckp end spout start spout end TP rpm CKP width sparkout width
ms ms ms ms % rpm
510489.61 510501.63 510496.83 510501.12 0 968 12.02 4.29
510520.58 510532.74 510527.79 510532.07 0 968 12.16 4.28
510551.82 510563.89 510559.17 510563.47 0 960 12.07 4.3
510740.65 510752.83 510747.84 510752.16 0 950 12.18 4.3199999999
511057.01 511069.27 511064.27 511068.59 0 949 12.26 4.32
511373.3 511385.44 511380.44 511384.75 0 956 12.14 4.31
511685.71 511697.85 511692.99 511697.29 0 960 12.14 4.3
511997.51 512009.63 512004.74 512009.03 0 964 12.12 4.29
512309.94 512322.15 512317.3 512321.62 0 952 12.21 4.32
512625.2 512637.48 512632.45 512636.78 0 945 12.28 4.33
....
689236.02 689239.5 689234.77 689238.27 0 3374 3.48 3.5
689325.29 689328.77 689324.03 689327.54 0 3351 3.48 3.51
689415.05 689418.56 689413.82 689417.32 0 3333 3.51 3.5
689505.68 689509.21 689504.45 689507.97 0 3296 3.5299999999 3.52
689596.9 689600.46 689595.7 689599.2 0 3282 3.5599999999 3.5
...
691201.52 691205.56 691200.59 691204.14 0 2887 4.04 3.55
691305.91 691309.98 691305.04 691308.54 0 2862 4.0699999999 3.5
691421.59 691425.7 691420.72 691424.24 0 2838 4.11 3.52
691527.7 691531.85 691526.87 691530.37 0 2819 4.15 3.5
691634.92 691639.11 691634.1 691637.63 0 2782 4.1899999999 3.53
691743.06 691747.28 691742.28 691745.77 0 2767 4.22 3.49
691852.3 691856.57 691851.53 691855.06 0 2732 4.2699999999 3.53
691962.6 691966.91 691961.89 691965.4 0 2712 4.3100000001 3.51
692073.97 692078.31 692073.26 692076.8 0 2683 4.3400000001 3.54
692186.24 692190.64 692185.58 692189.09 0 2661 4.4 3.51
692300 692304.44 692299.36 692302.89 0 2617 4.4399999999 3.53
692414.81 692419.28 692414.22 692417.71 0 2610 4.47 3.49
692530.64 692535.17 692530.05 692533.59 0 2572 4.53 3.5399999999
692647.91 692652.49 692647.37 692650.88 0 2551 4.58 3.51
692766.5 692771.13 692765.98 692769.51 0 2516 4.63 3.53
692886.51 692891.2 692886.05 692889.55 0 2489 4.6899999999 3.5
693007.9 693012.64 693007.43 693010.98 0 2459 4.74 3.5499999999
693130.7 693135.5 693130.29 693133.81 0 2433 4.8 3.52
693255.17 693260.03 693254.79 693258.33 0 2394 4.86 3.5399999999
693381.04 693385.97 693380.71 693384.23 0 2371 4.9299999999 3.52
693509.04 693514.05 693508.76 693512.29 0 2327 5.01 3.53
693638.8 693643.89 693638.57 693642.1 0 2297 5.09 3.53
693771.53 693776.74 693771.35 693774.91 0 2232 5.21 3.5600000001
693907.69 693913.05 693907.66 693911.18 0 2178 5.3600000001 3.52
694047.97 694053.51 694048.01 694051.59 0 2102 5.54 3.58
694192.92 694198.63 694193.11 694196.64 0 2047 5.71 3.53
694342.99 694348.93 694343.45 694346.89 0 1959 5.9400000001 3.4400000001
694499.06 694505.24 694499.82 694503.26 0 1892 6.1799999999 3.4400000001
694665.63 694672.61 694667.22 694670.66 0 1683 6.98 3.4400000001
694866.21 694875.08 694869.74 694873.49 0 1342 8.87 3.75
695136.95 695149.37 695144.36 695148.68 0 962 12.42 4.3200000001
695572.86 695593.39 695585.03 695590.97 0 571 20.53 5.9399999999
696066.16 696083.86 696076.84 696082.05 0 654 17.7 5.2100000001
696412.18 696420.68 696415.65 696419.33 9 1312 8.5 3.6799999999
696606.68 696613.65 696609.87 696613.34 14 1665 6.97 3.47
696782.78 696789.59 696785.8 696789.25 15 1717 6.8099999999 3.45
696972.28 696980.98 696977.16 696981.25 20 1370 8.7 4.09
697169.78 697176.69 697173.28 697176.79 60 1701 6.9099999999 3.51
697360.36 697367.38 697363.83 697367.57 91 1629 7.02 3.74
697530.21 697536.77 697533.23 697536.67 100 1795 6.5600000001 3.4400000001
697699.88 697706.14 697702.79 697706.23 100 1842 6.26 3.4399999999
697855.97 697862.06 697858.46 697861.91 100 1921 6.0900000001 3.4500000001
698009.25 698014.97 698011.39 698014.84 100 2021 5.72 3.45
698152.55 698158.11 698154.38 698157.89 100 2108 5.5599999999 3.51
698293.84 698299.18 698295.5 698299.01 100 2177 5.3400000001 3.51
698427.39 698432.54 698428.76 698432.27 100 2272 5.15 3.51
698558.78 698563.78 698560.03 698563.54 100 2327 5 3.51
698684.2 698689 698685.21 698688.72 100 2429 4.8 3.51
698806.5 698811.19 698807.43 698810.94 100 2471 4.6899999999 3.5099999999
698925.25 698929.81 698926.01 698929.52 100 2564 4.5600000001 3.51
699041.04 699045.48 699041.68 699045.19 100 2620 4.4399999999 3.5099999999
699153.69 699158 699154.17 699157.68 100 2700 4.3100000001 3.51
699263.51 699267.75 699263.75 699267.37 100 2762 4.24 3.62
699370.83 699374.96 699370.97 699374.57 100 2830 4.13 3.6
699527.33 699531.32 699527.42 699530.91 100 2932 3.99 3.49
699628.76 699632.7 699628.72 699632.28 100 2976 3.9399999999 3.5600000001
699728.85 699732.7 699728.77 699732.28 100 3030 3.85 3.51
699826.4 699830.16 699826.17 699829.74 100 3105 3.76 3.5699999999
699921.91 699925.61 699921.65 699925.17 100 3171 3.7 3.52
700015.91 700019.54 700015.49 700019.13 100 3205 3.63 3.64
700108.26 700111.85 700107.79 700111.39 100 3278 3.59 3.6
700199.17 700202.69 700198.62 700202.27 100 3329 3.5199999999 3.65
700288.75 700292.18 700288.12 700291.77 100 3378 3.4300000001 3.65
700376.58 700379.95 700375.92 700379.53 100 3452 3.37 3.61
700463.17 700466.53 700462.51 700466.09 100 3488 3.36 3.58
700548.67 700551.98 700547.94 700551.55 100 3537 3.3099999999 3.6100000001
700632.69 700635.92 700631.84 700635.49 100 3605 3.2300000001 3.65
700715.42 700718.6 700714.57 700718.19 100 3636 3.1799999999 3.62
700829.7 700832.81 700828.8 700832.4 100 3717 3.1100000001 3.6
700925.47 700928.51 700924.51 700928.1 100 3797 3.04 3.59
701004.31 701007.32 701003.27 701006.9 100 3807 3.0099999999 3.63
701082.35 701085.32 701081.3 701084.91 100 3875 2.97 3.61
701166.92 701169.85 701165.75 701169.45 100 3921 2.9299999999 3.7
701242.85 701245.8 701241.65 701245.33 100 3968 2.9500000001 3.6799999999
701318.04 701320.91 701316.76 701320.5 100 4005 2.87 3.74
....
969591.17 969597.29 969591.72 969595.17 0 1913 6.12 3.4500000001
969757.72 969764.57 969759.23 969762.68 0 1709 6.85 3.4500000001
969949.97 969958.13 969952.76 969956.41 0 1440 8.16 3.65
970182.24 970192.62 970187.4 970191.41 0 1148 10.38 4.01
970503.08 970518.59 970512.68 970517.44 0 773 15.51 4.7599999999
971030.16 971054.7 971045.37 971052.2 0 479 24.5399999999 6.83
971615.23 971635.34 971627.39 971633.47 0 570 20.11 6.08
972102.89 972121.02 972113.7 972119.06 0 636 18.13 5.3600000001
972555.23 972572.24 972565.24 972570.34 0 680 17.01 5.1
972978.54 972994.42 972988.08 972992.99 0 727 15.88 4.91
973382.53 973398.02 973392.12 973396.97 0 749 15.49 4.85
973777.9 973793.12 973787.53 973792.33 0 761 15.22 4.7999999999
974180.79 974196.79 974190.51 974195.49 0 727 16 4.98
974589.23 974604.87 974598.8 974603.68 0 740 15.64 4.88
974994.95 975010.71 975004.56 975009.51 0 738 15.76 4.95
975399.86 975415.45 975409.61 975414.47 0 744 15.59 4.86
975801.19 975816.75 975810.98 975815.83 0 747 15.5600000001 4.85
976204.41 976220.06 976214 976218.94 0 740 15.65 4.9399999999
976607.51 976623.14 976617.17 976622.03 0 744 15.63 4.86
977013.72 977029.51 977023.33 977028.23 0 733 15.79 4.9
