Theory Of Operation

The transmission relay is used to supply power to the solenoid pack when in normal operating mode and to turn off power to produce transmission "limp-in" mode. The relay output (which supplies power to the solenoid pack) is fed back to the controller This is referred to as SWITCHED BATTERY. After a controller reset (ignition key turned to the RUN position or after cranking engine), the controller verifies that the relay contacts are open by checking for no voltage on Switched battery line (relay output) before the relay is energized. Transmission locked in Limp-In. MIL on after 10 seconds of vehicle operation.