O/D Switch Rationality

NAME OF CODE
Overdrive Switch Low Rationality

WHEN MONITORED
The engine must have been running for a minimum of 10 seconds. The test for this code is executed every 440ms.

SET CONDITION
The overdrive off switch input is held low for 5 minutes or more from the time of closure or ignition on.

THEORY OF OPERATION
The overdrive switch is used to allow overdrive by allowing torque converter clutch operation at 30 MPH. Input is transition-based, meaning that the switch must close and open for data to be used. If overdrive is disabled for any reason, and the switch is shorted, the vehicle will continue in third-gear-only operation for the rest of the trip. Upon the next key on, overdrive will be available with no effect from the shorted switch.

POSSIBLE CAUSES
- Overdrive switch failure
- Shorted wire
- PCM failure