Here is a tough one but maybe someone will have an idea. I have an intermittent problem (the best kind). My 1998 HMC with an OM sometimes does not actually change tools. He just thinks he did. The first two times I assumed operator error jumping around in the program or something. This last time, I seen it myself. This is three times in about 4 months. Same parts have been running, one shift, 24 pcs per day. 13 tool changes per part. The machine is currently running but I'm waiting for the next mix-up.

Below, I attached the programs for your reference. I run program O1 as the main. O5011 is pallet one, O5012 is pallet two, O9003 is called up with M6.

After O5012, tool 55 is in the spindle, it pallet changes then is suppose to change to tool 60 to run O5011. This is where it made the mistake in the past and where I just seen it. It finished O5012 with tool 55 in the spindle (correct) changed pallets (correct), opened the tool change door (correct), but did not change tools, then closed the tool door and started machining with tool 55 rather than tool 60. And, it says tool 55 is in the spindle while running . I'm thinking its getting a false complete signal some how. Is this possible? I don't read ladders to know what it looks for and when. It did it last time with the same tool after O5012 so it be a program issue but we've made thousands of parts over the years with these programs. Maybe I need a "stop buffer" before or after tool changes or pallet changes? Any guidance will be appreciated.

O0001
T60
M61
M1
M98P5011
M1
M62
M1
M98P5012
M1
M99
%


%
O5011(CYLINDER OP 1)
M61
G00G91G80G40G28Z0
T60M6(1.25)
(STEPROUGH 3.057 BORE)
G54P1
T59
G00G90X0.0Y-0.899S5000M03
B0.
G43Z0.05H60M08
G01Z-0.35F75.
G03X0.0Y-0.899I0.0J0.899
G01Z-0.7
G03X0.0Y-0.899I0.0J0.899
(STEP1850BORE)
G01X0.2979Y0.Z-2.382F200.
G03X0.2979Y0.Z-2.64I-0.2979J0.0F75.
X0.2979Y0.Z-2.898I-0.2979J0.0
G01X0.0
G41D160Y-0.2982
G03X0.0Y-0.2982I0.0J0.2982
G01G40Y-0.2482
(STEPROUGH 1.617 BORE)
X0.1833Y0.
G03X0.1833Y0.0Z-3.175I-0.1833J0.0F75.
X0.1833Y0.0Z-3.5I-0.1833J0.0
G01X0.0
G41D160Y-0.1834
G03X0.0Y-0.1834I0.0J0.1834
G01G40Y-0.1334
(STEPROUGH BOTTOM)
G00Z0.15
G54P1
G00X-2.4Y2.41
G01Z-0.55F100.0
G41D160X-2.1
X2.1
G40X2.2
G00Z0.05
X-2.4
Z-0.5
G01Z-1.1F100.0
G41D160X-2.1
X2.1
G40X2.2
G00Z0.05
X-2.4
Z-1.05
G01Z-1.65F100.0
G41D160X-2.1
X2.1
G40X2.2
G00Z0.05
X-2.4
Z-1.6
G01Z-2.2F100.0
G41D160X-2.1
X2.1
G40X2.2
G00Z0.05
X-2.4
Z-2.15
G01Z-2.75F100.0
G41D160X-2.1
X2.1
G40X2.2
G00Z0.05
X-2.4
Z-2.7
G01Z-3.3F100.0
G41D160X-2.1
X2.1
G40X2.2
(STEP4)
G00Z.5
G54P1
G00X2.85Y-3.28
G01Z0.35F100.0
X-2.725
(STEPFACE Z0)
G00Z.5
G54P1
G00X-1.0827Y2.4204
G01Z0.0F100.0
G42D160X0.7836Y1.2555F75.
G02X-0.7836Y1.2555I-0.7836J-1.2555
G01G40X0.9131Y2.3145
(2XSTEP1850BORE)
G00Z.05
G00X0.0Y-0.0002
Z-2.382
G01Z-2.9F100.0
Y-0.2982F50.
G03X0.0Y-0.2982I0.0J0.2982
G01Y-0.2482
(STEPFACE BOSS)
G00Z8.0
G54P2
G00X0.0Y1.798
B180.
Z0.05
G01Z0.0F100.0
Y0.998
G02X0.0Y0.998I0.0J-0.998
G01Y1.598
(STEP 1.996 BOSS 1)
G00Z.05
G00X-2.7Y1.723
G01Z-0.19F100.0
X0.0
G02X0.0Y1.723I0.0J-1.723
G01X2.7
(STEP FACE EXHAUST)
G00Z0.5
G00X-3.325Y-2.723
G01Z-0.045F100.0
X2.5F75.
G0Z0.5
X-3.325Y-3.523
G1Z-0.045F100.
X2.5F75.
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T59M6(0.5)
(STEP1.996 BOSS 2)
G54P2
T58
G00G90X1.601Y-0.1625S3000M03
B180.
G43Z.05H59M08
G01Z-0.19F100.0
G41D159X0.8818Y-0.8818F20.0
G02X0.8818Y-0.8818I-0.8818J0.8818
G01G40X0.2686Y-1.4949
(STEP DRILL EXHAUST PORTS)
G00Z.05
G54P2
G00X0.7399Y-3.5043
G1Z-0.56F50.
G83Z-1.Q0.1F8.
G80
G01Z-0.84F100.
G41D159X0.7297Y-3.5482F10.0
G03X0.74Y-3.55I0.0103J0.0282
X0.74Y-3.55I0.0J0.0469
X0.7503Y-3.5482I0.0J0.03
G01G40X0.7401Y-3.5043
X0.7399
G01Z-1.15F10.
G41D159X0.7297Y-3.5482F10.0
G03X0.74Y-3.55I0.0103J0.0282
X0.7869Y-3.5031Z-1.25I0.J0.0469
X0.74Y-3.4562Z-1.15I-0.0469J0.
X0.74Y-3.55I0.J-0.0469
X0.7503Y-3.5482I0.0J0.03
G01G40X0.7401Y-3.5043
G00Z.05
X-0.7401
G1Z-0.56F50.
G83Z-1.Q0.1F8.
G80
G01Z-0.84F100.
G41D159X-0.7503Y-3.5482F10.0
G03X-0.74Y-3.55I0.0103J0.0282
X-0.74Y-3.55I0.0J0.0469
X-0.7297Y-3.5482I0.0J0.03
G01G40X-0.7399Y-3.5043
X-0.7401
G01Z-1.15F10.
G41D159X-0.7503Y-3.5482F10.0
G03X-0.74Y-3.55I0.0103J0.0282
X-0.74Y-3.4562I0.J0.0469
X-0.7869Y-3.5031Z-1.25I0.J-0.0469
X-0.74Y-3.55Z-1.15I0.0469J0.
X-0.7297Y-3.5482I0.0J0.03
G01G40X-0.7399Y-3.5043
(STEPMIDDLE EXHAUST PORT)
G00Z.05
G54P2
G00X-0.0021Y-3.4788
G01Z-0.79F8.0
G41D159X-0.0181Y-3.5469F10.0
G03X-0.001Y-3.55I0.0172J0.0469
X-0.001Y-3.55I0.0001J0.0469
X0.0161Y-3.547I0.0001J0.05
G01G40X0.0006Y-3.4788
(STEPFINISH BOTTOM B180)
G00Z.05
G54P2
G00X-2.3Y2.0315
G01Z-1.725F100.0
G41D159X-2.1F25.0
X2.1
G40X2.2
(STEP FINISH BOTTOM B0)
G00Z2.0
G54P1
G00X-2.3Y2.0315
B0.
Z0.05
G01Z-1.8F100.0
G41D159X-2.1F25.0
X-1.5
X-0.85Z-1.5
X0.85
X1.5Z-1.8
X2.1
G40X2.2
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T58M6(0.315)
(STEP SPOT 2 HOLES)
G54P1
T57
G00G90X1.025Y-3.09S3000M03
B0.
G43Z.408H58M08
G98G82Z0.225R0.408P100F15.0
X-1.025
G80
(STEP CHAMFER 1.85 BORE)
G54P1
G00X0.0Y-0.6377
Z-2.382
G01Z-2.49F100.0
G41D158Y-0.8377F30.0
G03X0.0Y-0.8377I0.0J0.8577
G01G40Y-0.7877
(STEPCHAMFER 90)
G00Z3.
G54P3
G00X1.2475Y1.8815
B90.
Z0.05
G01Z-0.06F100.0
G41D158Y1.7815F30.0
Y1.0251
G03X1.2657Y0.996I0.0325J0.0
G02X1.13Y0.4125I-0.1357J-0.276
G01X0.97
G03X0.9375Y0.38I0.0J-0.0325
G01Y-0.66
G03X0.97Y-0.6925I0.0325J0.0
G01X1.13
G02X1.13Y-1.3075I0.0J-0.3075
G01X0.97
G03X0.9375Y-1.34I0.0J-0.0325
G01Y-1.6835
G03X0.9394Y-1.6943I0.0325J0.0
G01X1.3287Y-2.7858
G03X1.3593Y-2.8075I0.0306J0.0108
G01X1.44
G02X1.44Y-3.4225I0.0J-0.3075
G01X1.309
G03X1.2795Y-3.4413I0.0J-0.0325
G02X0.8645Y-3.7803I-0.5595J0.2613
X0.8043Y-3.7875I-0.0603J0.2503
G01X-1.87
G02X-1.9275Y-3.73I0.0J0.0575
G01Y-3.115
G02X-1.87Y-3.0575I0.0575J0.0
G01X-1.7679
G03X-1.7365Y-3.0336I0.0J0.0325
G02X-1.44Y-2.8075I0.2965J-0.0814
G01X-1.3593
G03X-1.3287Y-2.7858I0.0J0.0325
G01X-0.9394Y-1.6943
G03X-0.9375Y-1.6835I-0.0306J0.0108
G01Y-1.33
G03X-0.97Y-1.2975I-0.0325J0.0
G01X-1.13
G02X-1.13Y-0.6825I0.0J0.3075
G01X-0.97
G03X-0.9375Y-0.65I0.0J0.0325
G01Y0.38
G03X-0.97Y0.4125I-0.0325J0.0
G01X-1.13
G02X-1.2657Y0.996I0.0J0.3075
G03X-1.2475Y1.0251I-0.0143J0.0292
G01Y1.08
G40X-1.2975
(STEP CHAMFER BOSS B180)
G00Z3.0
G54P2
G00X-0.5Y1.0605
B180.
Z0.05
G01Z-0.085F100.0
G41D158X0.0F40.0
G02X0.0Y1.0605I0.0J-1.0605
G01G40X0.1
(STEPCHAMFER 1.616 BORE)
G00Z.05
G54P2
G00X-0.1433Y-0.6191
G01Z-0.13F100.0
G41D158X-0.1Y-0.6641F50.0
G03X0.0Y-0.6909I0.1J0.1732
X0.0Y-0.6909I0.0J0.6909
X0.0684Y-0.6788I0.0J0.2
G01G40X0.0872Y-0.652
(STEPCHAMFER -90 SIDE)
G00Z3.
G54P4
G00X1.4475Y1.05
B-90.
Z0.05
G01Z-0.06F100.0
G41D158X1.2475F30.0
Y1.0251
G03X1.2657Y0.996I0.0325J0.0
G02X1.13Y0.4125I-0.1357J-0.276
G01X0.97
G03X0.9375Y0.38I0.0J-0.0325
G01Y-0.64
G03X0.97Y-0.6725I0.0325J0.0
G01X1.13
G02X1.13Y-1.2875I0.0J-0.3075
G01X0.97
G03X0.9375Y-1.32I0.0J-0.0325
G01Y-1.6835
G03X0.9394Y-1.6944I0.0325J0.0
G01X1.3287Y-2.7909
G03X1.3593Y-2.8125I0.0306J0.0109
G01X1.44
G02X1.7365Y-3.0386I0.0J-0.3075
G03X1.7679Y-3.0625I0.0313J0.0086
G01X1.87
G02X1.9275Y-3.12I0.0J-0.0575
G01Y-3.73
G02X1.87Y-3.7875I-0.0575J0.0
G01X-0.8043
G02X-0.8645Y-3.7803I0.0J0.2575
X-1.2773Y-3.446I0.1445J0.6003
G03X-1.3066Y-3.4275I-0.0293J-0.014
G01X-1.43
G02X-1.43Y-2.8125I0.0J0.3075
G01X-1.3493
G03X-1.3187Y-2.791I0.0J0.0325
G01X-0.9395Y-1.6948
G02X-0.9394Y-1.6944I0.0543J-0.0188
G03X-0.9375Y-1.6835I-0.0306J0.0109
G01Y-1.33
G03X-0.97Y-1.2975I-0.0325J0.0
G01X-1.13
G02X-1.13Y-0.6825I0.0J0.3075
G01X-0.97
G03X-0.9375Y-0.65I0.0J0.0325
G01Y0.38
G03X-0.97Y0.4125I-0.0325J0.0
G01X-1.13
G02X-1.2657Y0.996I0.0J0.3075
G03X-1.2475Y1.0251I-0.0143J0.0292
G01Y1.7815
G40Y1.8315
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T57M6(TRIPPLE BORE)
(STEP TRIPPLE BORE)
G54P1
T56
G00G90X0.0Y0.0S1500M03
B0.
G43Z0.H57M08
G1Z-3.2F100.
G98G85Z-4.034F4.
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T56M6(0.201)
(STEP DRILL 2)
G54P1
T55
G00G90X1.025Y-3.09S3000M03
B0.
G43Z.408H56M08
G98G83Z-0.292R0.408Q0.234F25.0
X-1.025
G80
(STEP 4 HOLES B0)
G54P1
G00X1.279Y-1.279
Z0.05
G98G81Z-0.55R0.05F60.0
X-1.279
Y1.279
X1.279
G80
(STEP SIDE HOLES B90)
G00Z2.0
G54P3
G00X1.13Y0.72
B90.
Z0.05
G98G81Z-0.58R0.05F60.0
Y-1.0
X1.44Y-3.12
X-1.44
X-1.13Y-1.0
Y0.72
G80
(STEPSIDE HOLES B-90)
G00Z2.0
G54P4
G00X1.13Y0.72
B-90.
Z0.05
G98G81Z-0.58R0.05F60.0
Y-1.0
X1.44Y-3.12
X-1.44
X-1.13Y-1.0
Y0.72
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T55M6(0.25)
(STEP TAP SIDE HOLES B-90)
G54P4
T54
G00G90X1.13Y0.72S800M03
B-90.
G43Z0.1H55M08
M29S800
G98G84Z-0.51R0.1F40.0
Y-1.0
X1.44Y-3.12
X-1.44
X-1.13Y-1.0
Y0.72
G80
(STEP TAP 2)
G00Z2.
G54P1
G00X1.025Y-3.09
B0.
Z0.408
M29S800
G98G84Z-0.222R0.408F40.0
X-1.025
G80
(STEP TAP 4 HOLES B0)
G54P1
G00X1.279Y-1.279
Z0.05
M29S800
G98G84Z-0.48R0.05F40.0
X-1.279
Y1.279
X1.279
G80
(STEP TAP SIDE HOLES B90)
G00Z2.0
G54P3
G00X1.13Y0.72
B90.
Z0.1
M29S800
G98G84Z-0.51R0.1F40.0
Y-1.0
X1.44Y-3.12
X-1.44
X-1.13Y-1.0
Y0.72
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T54M6(0.257)
(STEP DRILL MUFFLER HOLES)
G54P2
T53
G00G90X1.53Y-3.448S2000M03
B180.
G43Z.01H54M08
G98G81Z-0.84R0.01F40.
X-1.53
G80
(STEP DRILL 5-16 HOLES)
G54P2
G00X1.326Y-1.326
Z-0.14
G98G81Z-0.95R-0.14F40.
X-1.326
Y1.326
X1.326
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T53M6(0.312)
(STEP TAP 4 5-16 HOLES)
G54P2
T52
G00G90X1.326Y-1.326S720M03
B180.
G43Z-.14H53M08
M29S720
G98G84Z-0.89R-0.14F40.0
X-1.326
Y1.326
X1.326
G80
(STEP TAP MUFFLER HOLES)
G00Z.01
G54P2
G00X1.53Y-3.448
M29S720
G98G84Z-0.74R0.01F40.0
X-1.53
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M1
T52M6(0.4375)
(STEPPORT 5)
G54P5
T60
G00G90X0.9133Y-3.28S3000M03
B94.
G43Z7.635H52M08
Z1.735
G01Z1.36F2.5
G91Y-0.093Z-.6617
Y0.093Z.6617F50.
(STEPPORT 6)
G90G00Z7.635
G54P6
G00X0.6115Y-3.273
B107.
Z1.695
G01Z1.5F2.5
G91Y-0.093Z-.4784
Y0.093Z.4784F50.
(STEPPORT 7)
G90G00Z7.665
G54P7
G00X0.2873Y-3.26
B117.
Z1.765
G01Z1.65F2.5
G91Y-0.093Z-.3471
Y0.093Z.3471F50.
(STEPPORT8)
G90G00Z7.665
G54P8
G00X-0.2873Y-3.26
B-117.
Z1.755
G01Z1.65F2.5
G91Y-0.093Z-.3471
Y0.093Z.3471F50.
(STEP9)
G90G00Z7.655
G54P9
G00X-0.6115Y-3.273
B-107.
Z1.695
G01Z1.5F2.5
G91Y-0.093Z-.4784
Y0.093Z.4784F50.
(STEPPORT10)
G90G00Z7.635
G54P10
G00X-0.9133Y-3.28
B-94.
Z1.735
G01Z1.36F2.5
G91Y-0.093Z-.6617
Y0.093Z.6617F50.
M09
G00G91G28Z0
M05
G91G28Y0
M1
M99
%



%
O5012(CYLINDER OP 2)
M62
G00G91G80G40G28Z0
G00G91G28Y0
T60M6(1.25)
(STEP ENDS)
G54P11
T56
G00G90X2.05Y2.875S5000M03
B0.
G43Z0.1H60M08
G01Z-0.55F120.
G41D160Y2.775
G02X2.925Y1.9I0.0J-0.875
G01Y-1.9
G02X2.05Y-2.775I-0.875J0.0
G01G40Y-2.875
G00Z1.0
Y2.875
Z-0.525
G01Z-1.025F120.
G41D160Y2.775
G02X2.925Y1.9I0.0J-0.875
G01Y-1.9
G02X2.05Y-2.775I-0.875J0.0
G01G40Y-2.875
G00Z1.0
X-2.05
G01Z-0.55F120.
G41D160Y-2.775
G02X-2.925Y-1.9I0.0J0.875
G01Y1.9
G02X-2.05Y2.775I0.875J0.0
G01G40Y2.875
G00Z1.0
Y-2.875
Z-0.525
G01Z-1.025F120.
G41D160Y-2.775
G02X-2.925Y-1.9I0.0J0.875
G01Y1.9
G02X-2.05Y2.775I0.875J0.0
G01G40Y2.875
(STEP FACE)
G00Z1.0
G54P11
G00X0.4304Y0.0835
Z0.3
G01Z0.01F100.0
G41D160X0.95Y-0.2165F75.
G03X1.325Y0.0I0.125J0.2165
X1.325Y0.0I-1.325J0.0
X0.95Y0.2165I-0.25J0.0
G01G40X0.517Y-0.0335
G00X0.4304Y0.0835
G01Z0.0F100.0
G41D160X0.95Y-0.2165F75.
G03X1.325Y0.0I0.125J0.2165
X1.325Y0.0I-1.325J0.0
X0.95Y0.2165I-0.25J0.0
G01G40X0.517Y-0.0335
(STEP TERP OUTSIDE)
G00Z1.0
G54P11
G00X0.4052Y2.9508
Z0.05
G01Z-0.12F100.0
G41D160X1.678Y1.678F100.
G02X1.678Y1.678I-1.678J-1.678
G01G40X2.9508Y0.4052
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T56M6(0.238)
(STEP DRILL HOLES)
G54P11
T51
G00G90X1.52Y0.0S3000M03
G43Z0.05H56M08
G98G81Z-1.0R0.05F60.0
X1.0748Y1.0748
X0.0Y1.52
X-1.0748Y1.0748
X-1.52Y0.0
X-1.0748Y-1.0748
X0.0Y-1.52
X1.0748Y-1.0748
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T51M6(1.26)
(STEP UNDER CUT BORE)
G54P11
T58
G00G90X0.0Y0.4435S3000M03
G43Z0.05H51M08
G01Z-3.74F100.0
G41D151Y0.6435F15.0
G03X0.0Y0.6435I0.0J-0.6435
I0.J-0.6435F25.
G01G40Y0.4435
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T58M6(0.315)
(STEP CHAMFER OUTSIDE)
G54P11
T50
G00G90X1.1614Y1.4443S3000M03
G43Z0.05H58M08
G01Z-0.11F100.0
G41D158X1.3028Y1.3028F50.0
G02X1.3028Y1.3028I-1.3028J-1.3028
G01G40X1.3382Y1.2675
(STEP CHAMFER BORE)
G00Z0.05
G54P11
G00X0.2475Y0.9985
G01Z-0.14F100.0
G41D158X0.2828Y1.0338F50.0
G03X0.0Y1.151I-0.2828J-0.2828
X0.0Y1.151I0.0J-1.151
X-0.2828Y1.0338I0.0J-0.4
G01G40X-0.2475Y0.9985
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T50M6(2.537)
(STEP 2.537 BORE)
G54P11
T49
G00G90X0.0Y0.0S2000M3
G43Z0.05H50M08
G98G85Z-3.6R0.05F10.
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T49M6(2.537)
(HONE BORE)
G54P11
T55
G00G90X0.0Y0.0S200M03
G43Z0.05H49M08
G98G85Z-3.8R0.05F75.
X0.
M4
X0.Y0.
X0.
G80
M09
G00G91G28Z0
G00G91G28Y0
M05
M01
T55M6(0.25)
(STEP TAP HOLES)
G54P11
G00G90X1.52Y0.0S800M03
B0.
G43Z0.1H55M08
M29S800
G98G84Z-0.9R0.1F40.0
X1.0748Y1.0748
X0.0Y1.52
X-1.0748Y1.0748
X-1.52Y0.0
X-1.0748Y-1.0748
X0.0Y-1.52
X1.0748Y-1.0748
G80
(STEPTAP BOTTOM HOLES)
G00Z8.
G54P12
G00X-1.845Y0.97
B180.
Z2.6
M29S800
G98G84Z-0.6R0.1F40.0
X1.845
Y-0.89
X-1.845
G80
M09
G00G91G28Z0
M05
M1
M99
%




%
O9003
M9
G91G28Z0
G91G28Y0
M19
M6
M99
%