<s>
A	O
power-train	B-Device
control	I-Device
module	I-Device
,	O
abbreviated	O
PCM	O
,	O
is	O
an	O
automotive	O
component	O
,	O
a	O
control	O
unit	O
,	O
used	O
on	O
motor	O
vehicles	O
.	O
</s>
<s>
It	O
is	O
generally	O
a	O
combined	O
controller	O
consisting	O
of	O
the	O
engine	B-Device
control	I-Device
unit	I-Device
(	O
ECU	O
)	O
and	O
the	O
transmission	O
control	O
unit	O
(	O
TCU	O
)	O
.	O
</s>
<s>
Early	O
use	O
of	O
the	O
powertrain	B-Device
control	I-Device
module	I-Device
dates	O
back	O
to	O
the	O
late	O
1970s	O
-	O
official	O
phasing	O
in	O
of	O
the	O
PCM	O
occurred	O
during	O
the	O
early	O
1980s	O
when	O
used	O
in	O
conjunction	O
with	O
electronic	O
controlled	O
carburetors	O
and	O
lockup	O
torque	O
converters	O
(	O
at	O
the	O
time	O
conventional	O
3-speed	O
automatics	O
received	O
lockup	O
converters	O
at	O
the	O
same	O
time	O
overdrives	O
were	O
introduced	O
)	O
.	O
</s>
<s>
Engine	B-Device
control	I-Device
unit	I-Device
is	O
also	O
called	O
:	O
</s>
