Caravan FWD V6-3.8L VIN L (1999)
Transmission Control System Relay: Description and Operation
TRANSMISSION CONTROL RELAY
The transmission control relay is located in the Power Distribution Center (PDC) on the left side of the engine compartment. The relay is supplied
fused B+ voltage, energized by the TCM, and is used to supply power to the solenoid pack when the transmission is in normal operating mode. When
the relay is off, no power is supplied to the solenoid pack and the transmission is in limp-in mode. After a controller reset (ignition key turned to the
run position or after cranking engine), the TCM energizes the relay. Prior to this, the TCM verifies that the contacts are open by checking for no
voltage at the switched battery terminals. After this is verified, the voltage at the solenoid pack pressure switches is checked. After the relay is
energized, the TCM monitors the terminals to verify that the voltage is greater than 3 volts.
