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Help with TC Lockup Switch

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Old 02-24-2004, 01:26 PM
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Default Help with TC Lockup Switch

I am trying to hook up a manual lock up switch for my torque converter on my 98 Transam. I need to know which wire from the PCM to splice into. Thanks.
Old 02-24-2004, 03:16 PM
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Here are the color codes, at the transmission
connector (20-pin round). This is probably a
good place to get ahold of them (if you like
soldering upside-down) as they're right close
to where you'd be putting the switches (but
on the other side of the sheet metal). The
colors "should" be the same at the PCM connectors
but there you have a lot of duplication to weed
through. You probably want a handy PCM pin chart
if you intend to work up there.

Pin Color Function
A LtGrn 1-2 Solenoid
B Yel/Blk 2-3 Solenoid
C Red/Blk Pressure control (PC) solenoid valve, high control
D LtBlu/Wht PC solenoid valve low control
E Pnk IGN
F-K ------ Not used
L Yel/Blk Transmission Fluid Temp sensor
M Gry Low reference 3.8L
M Blk Low Reference 5.7L
N Pnk TFP Switch Signal A
P Red TFP Switch Signal C
R DkBlu TFP Switch Signal B
S Wht 3-3 Shift Solenoid Valve Control
T Tan/Blk Torque Converter Clutch solenoid valve control
U Brn Torque Converter Clutch PWM solenoid valve control

Notes: transcribed from 2002 Helm manual Vol3/3 Pg 7-123
"TFP" = transmission fluid pressure switch logic from manual valve body

TFP Signals w/ Gear Selector:

Gear SigA Sig B Sig C
P Hi Low Hi
R Low Low Hi
N Hi Low Hi
D4 Hi Low Low
D3 Hi Hi Low
D2 Hi Hi Hi
D1 Low Hi Hi

Other codes are invalid
Hi = IGN, Lo = 0 voltage


You want to ground the Tan/Blk wire to apply the TCC and
you probably have to do something with the PWM solenoid
as well to get full pressure. But I don't know what. If I had to
guess I'd ground that too. Not that I recommend guessing.
Probably best to hook up a DVM and see what these two wires
get up to during normal operation, TCC locked, and go from
there.

Also unknown to me are any faults that might be caught from
jamming these signals to ground on a continuous basis, or from
making an open circuit as seen by the PCM (if, say, you wanted
a complementary force-converter-unlock switch for cruising
around town, you would open-circuit the Tan/Blk)

Solenoid resistance for TCC Solenoid: 24 ohms
Solenoid resistance for TCC PWM Solenoid: 12 ohms

So you would be running a 1A current and probably
want at least a 2A rated relay or switch. If you were
going to disconnect these solenoids from the PWM you
might want to present it a dummy load of the right
value, to keep it happy.
Old 09-01-2008, 09:22 PM
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Originally Posted by 1jfuddle
I am trying to hook up a manual lock up switch for my torque converter on my 98 Transam. I need to know which wire from the PCM to splice into. Thanks.
I have read many post about this. Not all my questions have been answered however most of them have

run a wire from TCC Solenoid to one side of the toggle switch and and on the other side on the toggle switch run a wire to a good ground

you will need to do the same with the PWN Solenoid except instead of ground you will need to use the ignition +12v

On a side note 98 models have different pinouts than 99 and up.
these are the pins you need for a 1998
32 BRN 422 TCC Enable Solenoid
33 BRN 418 TCC (PWM) Solenoid

and 99 and up are

42 tan/black TCC Enable Solenoid
?? ???/??? PWM Solenoid

If any of this is inaccurate or could be worded better please do so.... Also for the 99 and up models what wire and color is the PWM Solenoid?



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