S10/T10 Blazer 4WD V6-262 4.3L VIN Z (1994)
Control Module: Description and Operation
TCCM Inputs and Outputs
General Description
INPUTS
The Transfer Case Control Module (TCCM) receives input signals from the following sources:
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Transfer case selector switch on the instrument panel.
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Park/neutral position switch on vehicles with automatic transmissions.
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Clutch safety switch on vehicles with manual transmissions.
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Vehicle speed sensor buffer which supplies vehicle speed signals.
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Encoder switch within the electric-shift motor which provides actual mode and range information signals.
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Data link connector (DLC) pin J which provides diagnostic enable.
OUTPUTS
After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following:
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Electric shift motor to effect mode and range shifts.
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Selector switch status lamps to provide transfer case status information.
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Diagnostic trouble codes (DTC) which are output via the selector switch status lamps.
2HI to 4HI Selector Switch Input
4WD Selector Switch Wiring Schematic
OPERATION
When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close,
connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer
Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is
released.
4HI to 2HI Selector Switch Input