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Transmission Limp-In

The normal or default state for the transmission when the transmission range in D or OD and no solenoids are energized is 2nd gear. The solenoids are controlled by the transmission controller with solenoid electrical power supplied through the transmission relay which is also controlled by the transmission controller.
When the transmission controller detects a malfunction which prevents continued safe transmission operation, either in the controller itself, it's sensors, or a mechanical failure in the transmission, ALL electrical control is abandoned causing (LIMP-IN). The controller does this by turning off the transmission relay, which removes all electrical power from the solenoids. The transmission will be in the mechanical default state of 2nd gear. No recovery from this condition is possible until the ignition switch is cycled or fault is corrected. Park, Reverse and neutral are still available through the mechanical linkage of the transmission.