B&M 70244 CONVERTER LOCKUP CNTRL - Manual (Page 4)

4
continuously. In the later units the
ECU is used to energize the solenoid
at the appropriate speed by providing
an external ground to the solenoid. In
all of the above cases control pressure
becomes available only after the trans-
mission shifts out of first gear. Hence
the torque converter clutch will never
lock-up in first gear. The converter
clutch solenoid is located inside the
transmission, as are the converter
clutch apply valve and, if equipped,
Converter Clutch Shift Valve. Access
to these components requires oil pan
removal. Some applications may re-
quire inspection or modification of these
components.
The lock-up solenoid is connected to
a four pin (some early units have two
pins) connector located on the trans-
mission case. The pins on these con-
nectors are identified by the letters A,
B, C and D.
Lock-up solenoids come with either
one or two wires. The one wire style is
internally grounded and requires only
a +12V connection to energize. One
wire solenoids are generally hooked
up to connector pin A, see Figure 3.
Two wire solenoids require both +12V
and ground connections to operate.
Two wire solenoids are usually hooked
up to pins A and D, where A is +12V
and D is ground, see Figure 4. De-
pending on the application one or both
of the solenoid wires may also be
connected to pressure switches on the
valve body either before, or instead of,
going to pin D. Reversing the polarity
on a two wire solenoid can damage an
internal diode which protects the elec-
trical system from voltage spikes.
TOOLS
Besides the normal electrical repair
tools, i.e. wire cutters, stripper and
terminal crimper, a VOM (Volt Ohm
Meter, or at the very least a 12V test
light) is required to check voltage polar-
ity and circuit continuity. Incorrect po-
larity connections or short circuits will
damage the Converter Lock-Up Con-
trol electronic module and void the
warranty.
Figure 4
Transmission
electrical connector
pin identification
TCC & brake
switch
ECU
TCC sole-
noid
TCC sole-
noid
TCC sole-
noid
ECU
EGR solenoid
3rd gear switch
MX2 only
Governor switch N.O.
Vacuum valve
throttle switch
4th gear switch
Transmission
Transmission
TCC applies in
2nd, 3rd or 4th
gear under ECU
control
TH-200-4R
TH-700-R4
TCC applies in 3rd
gear only
TH-350- MV4,
MX2
TH-200C - MV9
TCC applies in
3rd gear only un-
der ECU control
TH-350C - MV4,
MX2
TH-250C - M31
TH-200C - MY9
A
B
D
3rd gear switch
MX2 only
4th gear pulse
switch
TCC &
brake
switch
TCC & brake
switch
A A
D D
B B
A A
D D
A A
D
D
Note: The above illustrations
for reference only. Your particu-
lar unit may not have all compo-
nents shown.
Transmission
TCC solenoid
TCC & brake
switch
+12 V
Figure 3
Transmission